gnu: ghc-mtl: Remove built-in Haskell package.

* gnu/packages/agda.scm (agda)[inputs]: Remove ghc-mtl.
* gnu/packages/games.scm (raincat)[inputs]: Remove ghc-mtl.
* gnu/packages/haskell-check.scm (ghc-tasty-ant-xml, ghc-tasty-golden,
ghc-tasty, ghc-tasty-kat, ghc-tasty-rerun,
ghc-crypto-cipher-tests)[inputs]: Remove ghc-mtl.
* gnu/packages/haskell-crypto.scm (ghc-asn1-encoding, ghc-pem, ghc-x509,
ghc-x509-store, ghc-x509-validation, ghc-x509-system)[inputs]: Remove
ghc-mtl.
* gnu/packages/haskell-web.scm (ghc-http, ghc-http-conduit,
ghc-yesod-core)[inputs]: Remove ghc-mtl.
* gnu/packages/haskell.scm (ghc-convertible, ghc-libxml, ghc-cgi,
ghc-happy, ghc-haskell-src-exts, ghc-resourcet, cabal-install,
ghc-indents, ghc-regex-base, ghc-regex-tdfa-rc, ghc-trifecta,
ghc-zip-archive, ghc-logict, ghc-exceptions, ghc-smallcheck, ghc-syb,
ghc-fgl, ghc-chasingbottoms, ghc-parsec, ghc-megaparsec, ghc-edisonapi,
ghc-edisoncore, ghc-mmorph, ghc-ifelse, ghc-kan-extensions, ghc-lens,
ghc-cheapskate, ghc-free, ghc-adjunctions, ghc-equivalence, ghc-texmath,
ghc-texmath-for-pandoc-1, ghc-highlighting-kate, ghc-th-reify-many,
ghc-th-orphans, ghc-geniplate-mirror, ghc-conduit, ghc-filemanip,
ghc-juicypixels, ghc-hslua, ghc-hourglass, ghc-skylighting,
ghc-skylighting-for-pandoc-1, ghc-pandoc, ghc-pandoc-1,
ghc-pandoc-citeproc, ghc-regex-tdfa, ghc-stmonadtrans, ghc-constraints,
ghc-lifted-async, ghc-shelly, ghc-hslogger, ghc-json, shellcheck,
ghc-vector-algorithms, ghc-monad-par-extras, ghc-monad-par,
ghc-monadrandom, ghc-either, ghc-rebase, ghc-aws, ghc-monad-logger,
ghc-persistent, ghc-bytes, ghc-missingh, ghc-operational,
ghc-chart)[inputs]: Remove ghc-mtl.
(ghc-conduit-combinators)[native-inputs]: Remove ghc-mtl.
(ghc-mtl): Remove variable.
* gnu/packages/idris.scm (idris)[inputs]: Remove ghc-mtl.
* gnu/packages/tls.scm (ghc-tls)[inputs]: Remove ghc-mtl.
* gnu/packages/version-control.scm (darcs, git-annex)[inputs]: Remove
ghc-mtl.
* gnu/packages/wm.scm (xmonad, ghc-xmonad-contrib)[inputs]: Remove
ghc-mtl.
* gnu/packages/xml.scm (ghc-hxt)[inputs]: Remove ghc-mtl.

gnu/packages/agda.scm

@@ -58,7 +58,6 @@
        ("ghc-hashtables" ,ghc-hashtables)
        ("ghc-ieee754" ,ghc-ieee754)
        ("ghc-monadplus" ,ghc-monadplus)
-       ("ghc-mtl" ,ghc-mtl)
        ("ghc-murmur-hash" ,ghc-murmur-hash)
        ("ghc-uri-encode" ,ghc-uri-encode)
        ("ghc-parallel" ,ghc-parallel)

gnu/packages/games.scm

@@ -2136,7 +2136,6 @@ on the screen and keyboard to display letters.")
     (build-system haskell-build-system)
     (inputs
      `(("ghc-extensible-exceptions" ,ghc-extensible-exceptions)
-       ("ghc-mtl" ,ghc-mtl)
        ("ghc-random" ,ghc-random)
        ("ghc-glut" ,ghc-glut)
        ("freeglut" ,freeglut)

gnu/packages/haskell-check.scm

@@ -54,7 +54,6 @@
     (inputs
      `(("ghc-generic-deriving" ,ghc-generic-deriving)
        ("ghc-xml" ,ghc-xml)
-       ("ghc-mtl" ,ghc-mtl)
        ("ghc-stm" ,ghc-stm)
        ("ghc-tagged" ,ghc-tagged)
        ("ghc-tasty" ,ghc-tasty)))
@@ -140,7 +139,6 @@ Haskell test framework.")
     (inputs
      `(("ghc-temporary" ,ghc-temporary)
        ("ghc-tasty" ,ghc-tasty)
-       ("ghc-mtl" ,ghc-mtl)
        ("ghc-optparse-applicative" ,ghc-optparse-applicative)
        ("ghc-tagged" ,ghc-tagged)
        ("ghc-async" ,ghc-async)
@@ -197,7 +195,6 @@ timer functions of different operating systems via a unified API.")
     (build-system haskell-build-system)
     (inputs
      `(("ghc-stm" ,ghc-stm)
-       ("ghc-mtl" ,ghc-mtl)
        ("ghc-tagged" ,ghc-tagged)
        ("ghc-regex-tdfa" ,ghc-regex-tdfa)
        ("ghc-regex-tdfa-rc" ,ghc-regex-tdfa-rc)
@@ -250,7 +247,6 @@ test framework.")
     (build-system haskell-build-system)
     (inputs
      `(("ghc-tasty" ,ghc-tasty)
-       ("ghc-mtl" ,ghc-mtl)
        ("ghc-tasty-quickcheck" ,ghc-tasty-quickcheck)
        ("ghc-tasty-hunit" ,ghc-tasty-hunit)))
     (home-page "https://github.com/vincenthz/tasty-kat")
@@ -299,8 +295,7 @@ test-framework.")
                 "0yg8cicfn3qaazvp4rbanzy3dyk95k3y1kkd4bykvkl9v4076788"))))
     (build-system haskell-build-system)
     (inputs
-     `(("ghc-mtl" ,ghc-mtl)
+     `(("ghc-optparse-applicative" ,ghc-optparse-applicative)
-       ("ghc-optparse-applicative" ,ghc-optparse-applicative)
        ("ghc-reducers" ,ghc-reducers)
        ("ghc-split" ,ghc-split)
        ("ghc-stm" ,ghc-stm)
@@ -827,7 +822,6 @@ minimal dependencies.")
          "19wqignlq90qwpam01hnmmrxaxh5lkax9l1l6rlbi4a07nvp1dnz"))))
     (build-system haskell-build-system)
     (inputs `(("ghc-quickcheck" ,ghc-quickcheck)
-              ("ghc-mtl" ,ghc-mtl)
               ("ghc-hunit" ,ghc-hunit)
               ("ghc-test-framework" ,ghc-test-framework)
               ("ghc-test-framework-quickcheck2" ,ghc-test-framework-quickcheck2)

gnu/packages/haskell-crypto.scm

@@ -70,8 +70,7 @@ format.")
     (inputs
      `(("ghc-hourglass" ,ghc-hourglass)
        ("ghc-asn1-types" ,ghc-asn1-types)
-       ("ghc-text" ,ghc-text)
+       ("ghc-text" ,ghc-text)))
-       ("ghc-mtl" ,ghc-mtl)))
     (native-inputs
      `(("ghc-tasty" ,ghc-tasty)
        ("ghc-tasty-quickcheck" ,ghc-tasty-quickcheck)))
@@ -345,8 +344,7 @@ to obtain cryptographically strong entropy.")
                 "162sk5sg22w21wqz5qv8kx6ibxp99v5p20g3nknhm1kddk3hha1p"))))
     (build-system haskell-build-system)
     (inputs
-     `(("ghc-mtl" ,ghc-mtl)
+     `(("ghc-base64-bytestring" ,ghc-base64-bytestring)))
-       ("ghc-base64-bytestring" ,ghc-base64-bytestring)))
     (native-inputs
      `(("ghc-test-framework" ,ghc-test-framework)
        ("ghc-test-framework-quickcheck2" ,ghc-test-framework-quickcheck2)
@@ -431,7 +429,6 @@ libraries, like OpenSSL.")
     (build-system haskell-build-system)
     (inputs
      `(("ghc-memory" ,ghc-memory)
-       ("ghc-mtl" ,ghc-mtl)
        ("ghc-hourglass" ,ghc-hourglass)
        ("ghc-pem" ,ghc-pem)
        ("ghc-asn1-types" ,ghc-asn1-types)
@@ -461,8 +458,7 @@ libraries, like OpenSSL.")
                 "0yw09nwkvr324qz4sc27c0p28bz2h6gns6lkaz9mz92mgqf2dza9"))))
     (build-system haskell-build-system)
     (inputs
-     `(("ghc-mtl" ,ghc-mtl)
+     `(("ghc-pem" ,ghc-pem)
-       ("ghc-pem" ,ghc-pem)
        ("ghc-asn1-types" ,ghc-asn1-types)
        ("ghc-asn1-encoding" ,ghc-asn1-encoding)
        ("ghc-cryptonite" ,ghc-cryptonite)
@@ -490,7 +486,6 @@ collections, certificates, revocation lists, and exception lists.")
     (inputs
      `(("ghc-memory" ,ghc-memory)
        ("ghc-byteable" ,ghc-byteable)
-       ("ghc-mtl" ,ghc-mtl)
        ("ghc-hourglass" ,ghc-hourglass)
        ("ghc-data-default-class" ,ghc-data-default-class)
        ("ghc-pem" ,ghc-pem)
@@ -520,8 +515,7 @@ list validation.")
                 "0k7zc0xp7r6kqmi39rpiicvq78xb0pr2cq6q5s3kmmsshllg13nr"))))
     (build-system haskell-build-system)
     (inputs
-     `(("ghc-mtl" ,ghc-mtl)
+     `(("ghc-pem" ,ghc-pem)
-       ("ghc-pem" ,ghc-pem)
        ("ghc-x509" ,ghc-x509)
        ("ghc-x509-store" ,ghc-x509-store)))
     (home-page "https://github.com/vincenthz/hs-certificate")

gnu/packages/haskell-web.scm

@@ -171,7 +171,6 @@ both client and server code).")
        ("ghc-old-time" ,ghc-old-time)
        ("ghc-parsec" ,ghc-parsec)
        ("ghc-puremd5" ,ghc-puremd5)
-       ("ghc-mtl" ,ghc-mtl)
        ("ghc-network" ,ghc-network)
        ("ghc-network-uri" ,ghc-network-uri)
        ("ghc-split" ,ghc-split)))
@@ -350,7 +349,6 @@ and HPACK.  Currently HTTP/2 16 framing and HPACK 10 is supported.")
        ("ghc-http-client" ,ghc-http-client)
        ("ghc-http-client-tls" ,ghc-http-client-tls)
        ("ghc-monad-control" ,ghc-monad-control)
-       ("ghc-mtl" ,ghc-mtl)
        ("ghc-exceptions" ,ghc-exceptions)
        ("ghc-unliftio" ,ghc-unliftio)))
     (native-inputs
@@ -1039,7 +1037,6 @@ avoid any issues with characters.")
               ("ghc-text" ,ghc-text)
               ("ghc-shakespeare" ,ghc-shakespeare)
               ("ghc-blaze-builder" ,ghc-blaze-builder)
-              ("ghc-mtl" ,ghc-mtl)
               ("ghc-clientsession" ,ghc-clientsession)
               ("ghc-random" ,ghc-random)
               ("ghc-cereal" ,ghc-cereal)

gnu/packages/haskell.scm

@@ -596,7 +596,6 @@ determine the hostname.")
     (inputs
      `(("ghc-old-time" ,ghc-old-time)
        ("ghc-old-locale" ,ghc-old-locale)
-       ("ghc-mtl" ,ghc-mtl)
        ("ghc-text" ,ghc-text)))
     (home-page "https://hackage.haskell.org/package/convertible")
     (synopsis "Typeclasses and instances for converting between types")
@@ -649,8 +648,7 @@ between double precision floating point and text.")
          "01zvk86kg726lf2vnlr7dxiz7g3xwi5a4ak9gcfbwyhynkzjmsfi"))))
     (build-system haskell-build-system)
     (inputs
-     `(("ghc-mtl" ,ghc-mtl)
+     `(("libxml2" ,libxml2)))
-       ("libxml2" ,libxml2)))
     (arguments
      `(#:configure-flags
        `(,(string-append "--extra-include-dirs="
@@ -1041,8 +1039,7 @@ tool lex or flex for C/C++.")
        ("ghc-exceptions" ,ghc-exceptions)
        ("ghc-multipart" ,ghc-multipart)
        ("ghc-network-uri" ,ghc-network-uri)
-       ("ghc-network" ,ghc-network)
+       ("ghc-network" ,ghc-network)))
-       ("ghc-mtl" ,ghc-mtl)))
     (native-inputs
      `(("ghc-doctest" ,ghc-doctest)
        ("ghc-quickcheck" ,ghc-quickcheck)))
@@ -1111,8 +1108,6 @@ postfix notation.  For more information on stack based languages, see
         (base32
          "186ky3bly0i3cc56qk3r7j7pxh2108aackq4n2lli7jmbnb3kxsd"))))
     (build-system haskell-build-system)
-    (inputs
-     `(("ghc-mtl" ,ghc-mtl)))
     (home-page "https://hackage.haskell.org/package/happy")
     (synopsis "Parser generator for Haskell")
     (description "Happy is a parser generator for Haskell.  Given a grammar
@@ -1199,7 +1194,6 @@ examination.")
     (inputs
      `(("cpphs" ,cpphs)
        ("ghc-happy" ,ghc-happy)
-       ("ghc-mtl" ,ghc-mtl)
        ("ghc-pretty-show" ,ghc-pretty-show-for-haskell-src-exts)))
     (native-inputs
      `(("ghc-smallcheck" ,ghc-smallcheck)
@@ -1317,7 +1311,6 @@ unwanted suggestions, and to add your own custom suggestions.")
      `(("ghc-transformers-base" ,ghc-transformers-base)
        ("ghc-monad-control" ,ghc-monad-control)
        ("ghc-transformers-compat" ,ghc-transformers-compat)
-       ("ghc-mtl" ,ghc-mtl)
        ("ghc-mmorph" ,ghc-mmorph)
        ("ghc-exceptions" ,ghc-exceptions)
        ("ghc-unliftio-core" ,ghc-unliftio-core)))
@@ -1812,7 +1805,6 @@ versions of GHC (i.e., < 6.10).")
    (build-system haskell-build-system)
    (inputs
     `(("ghc-http" ,ghc-http)
-      ("ghc-mtl" ,ghc-mtl)
       ("ghc-network-uri" ,ghc-network-uri)
       ("ghc-network" ,ghc-network)
       ("ghc-random" ,ghc-random)
@@ -1848,37 +1840,6 @@ configuration.  This library provides the common bits for writing custom
 @file{Setup.hs} files.")
     (license license:bsd-3)))
 
-(define-public ghc-mtl
-  (package
-    (name "ghc-mtl")
-    (version "2.2.1")
-    (outputs '("out" "doc"))
-    (source
-     (origin
-       (method url-fetch)
-       (uri (string-append
-             "https://hackage.haskell.org/package/mtl/mtl-"
-             version
-             ".tar.gz"))
-       (sha256
-        (base32
-         "1icdbj2rshzn0m1zz5wa7v3xvkf6qw811p4s7jgqwvx1ydwrvrfa"))))
-    (build-system haskell-build-system)
-    ;; This is an official revision, relaxing the requirement transformers ==
-    ;; 0.4 to transformers >= 0.4 && < 0.6; see
-    ;; https://hackage.haskell.org/package/mtl-2.2.1/revision/1.cabal
-    (arguments
-     `(#:configure-flags (list "--allow-newer=transformers")))
-    (home-page "https://github.com/ekmett/mtl")
-    (synopsis
-     "Monad classes, using functional dependencies")
-    (description "Monad classes using functional dependencies, with instances
-for various monad transformers, inspired by the paper 'Functional Programming
-with Overloading and Higher-Order Polymorphism', by Mark P Jones, in 'Advanced
-School of Functional Programming', 1995.  See
-@uref{https://web.cecs.pdx.edu/~mpj/pubs/springschool.html, the paper}.")
-    (license license:bsd-3)))
-
 (define-public ghc-parsec-numbers
   (package
     (name "ghc-parsec-numbers")
@@ -2535,8 +2496,7 @@ isn't available, portable implementations are used.")
     (build-system haskell-build-system)
     (inputs
      `(("ghc-parsec" ,ghc-parsec)
-       ("ghc-concatenative" ,ghc-concatenative)
+       ("ghc-concatenative" ,ghc-concatenative)))
-       ("ghc-mtl" ,ghc-mtl)))
     (home-page "http://patch-tag.com/r/salazar/indents")
     (synopsis "Indentation sensitive parser-combinators for parsec")
     (description
@@ -2611,8 +2571,6 @@ supported systems.")
         (base32
          "0y1j4h2pg12c853nzmczs263di7xkkmlnsq5dlp5wgbgl49mgp10"))))
     (build-system haskell-build-system)
-    (inputs
-     `(("ghc-mtl" ,ghc-mtl)))
     (home-page
      "https://sourceforge.net/projects/lazy-regex")
     (synopsis "Replaces/Enhances Text.Regex")
@@ -2684,8 +2642,7 @@ Haskell library @code{regex-base}.")
     (build-system haskell-build-system)
     (inputs
      `(("ghc-regex-base" ,ghc-regex-base)
-       ("ghc-parsec" ,ghc-parsec)
+       ("ghc-parsec" ,ghc-parsec)))
-       ("ghc-mtl" ,ghc-mtl)))
     (home-page
      "https://hackage.haskell.org/package/regex-tdfa")
     (synopsis "Tagged DFA regex engine for Haskell")
@@ -2815,7 +2772,6 @@ the parsers provided by @code{parsec}, @code{attoparsec} and @code{base}'s
        ("ghc-fingertree" ,ghc-fingertree)
        ("ghc-hashable" ,ghc-hashable)
        ("ghc-lens" ,ghc-lens)
-       ("ghc-mtl" ,ghc-mtl)
        ("ghc-parsers" ,ghc-parsers)
        ("ghc-profunctors" ,ghc-profunctors)
        ("ghc-quickcheck" ,ghc-quickcheck)
@@ -2904,7 +2860,6 @@ complicated text/binary file formats.")
      `(("ghc-old-time" ,ghc-old-time)
        ("ghc-digest" ,ghc-digest)
        ("zip" ,zip)
-       ("ghc-mtl" ,ghc-mtl)
        ("ghc-temporary" ,ghc-temporary)
        ("ghc-text" ,ghc-text)
        ("ghc-zlib" ,ghc-zlib)))
@@ -3249,7 +3204,6 @@ syntax and semantics as Perl 5.")
         (base32
          "07hnirv6snnym2r7iijlfz00b60jpy2856zvqxh989q0in7bd0hi"))))
     (build-system haskell-build-system)
-    (inputs `(("ghc-mtl" ,ghc-mtl)))
     (home-page "http://code.haskell.org/~dolio/")
     (synopsis "Backtracking logic-programming monad")
     (description "This library provides a continuation-based, backtracking,
@@ -3332,7 +3286,6 @@ consuming feeds in both RSS (Really Simple Syndication) and Atom format.")
        ("ghc-test-framework-quickcheck2" ,ghc-test-framework-quickcheck2)))
     (inputs
      `(("ghc-stm" ,ghc-stm)
-       ("ghc-mtl" ,ghc-mtl)
        ("ghc-transformers-compat" ,ghc-transformers-compat)))
     (home-page "https://github.com/ekmett/exceptions/")
     (synopsis "Extensible optionally-pure exceptions")
@@ -3410,8 +3363,7 @@ This is a better maintained fork of the \"temporary\" package.")
          "195fj7w3v03d1y1nm2ylavzrwxjcdbq0lb6zsw1dwyx5jmwfc84h"))))
     (build-system haskell-build-system)
     (inputs
-     `(("ghc-logict" ,ghc-logict)
+     `(("ghc-logict" ,ghc-logict)))
-       ("ghc-mtl" ,ghc-mtl)))
     (home-page
      "https://github.com/feuerbach/smallcheck")
     (synopsis "Property-based testing library")
@@ -3495,8 +3447,7 @@ to cases.")
          "1p3cnqjm13677r4a966zffzhi9b3a321aln8zs8ckqj0d9z1z3d3"))))
     (build-system haskell-build-system)
     (inputs
-     `(("ghc-hunit" ,ghc-hunit)
+     `(("ghc-hunit" ,ghc-hunit)))
-       ("ghc-mtl" ,ghc-mtl)))
     (home-page
      "http://www.cs.uu.nl/wiki/GenericProgramming/SYB")
     (synopsis "Scrap Your Boilerplate")
@@ -3528,8 +3479,7 @@ variety of traversals.")
      `(#:configure-flags (list "--allow-newer=QuickCheck"
                                "--allow-newer=hspec")))
     (inputs
-     `(("ghc-mtl" ,ghc-mtl)
+     `(("ghc-hspec" ,ghc-hspec)
-       ("ghc-hspec" ,ghc-hspec)
        ("ghc-quickcheck" ,ghc-quickcheck)))
     (home-page "https://web.engr.oregonstate.edu/~erwig/fgl/haskell")
     (synopsis
@@ -3554,8 +3504,7 @@ encourages inductive, recursive definitions of graph algorithms.")
          "04jwwjs22mqc4hvpp4c3gpb79inrrq5sapks5khknspv2hslm61q"))))
     (build-system haskell-build-system)
     (inputs
-     `(("ghc-mtl" ,ghc-mtl)
+     `(("ghc-quickcheck" ,ghc-quickcheck)
-       ("ghc-quickcheck" ,ghc-quickcheck)
        ("ghc-random" ,ghc-random)
        ("ghc-syb" ,ghc-syb)))
     (home-page "https://hackage.haskell.org/package/ChasingBottoms")
@@ -3764,8 +3713,7 @@ mainstream languages.")
     (native-inputs
      `(("ghc-hunit" ,ghc-hunit)))
     (inputs
-     `(("ghc-text" ,ghc-text)
+     `(("ghc-text" ,ghc-text)))
-       ("ghc-mtl" ,ghc-mtl)))
     (arguments
      `(#:tests? #f)) ; FIXME: currently missing libraries used for tests.
     (home-page
@@ -3814,7 +3762,6 @@ combinators.")
     (build-system haskell-build-system)
     (inputs
      `(("ghc-case-insensitive" ,ghc-case-insensitive)
-       ("ghc-mtl" ,ghc-mtl)
        ("ghc-parser-combinators" ,ghc-parser-combinators)
        ("ghc-scientific" ,ghc-scientific)
        ("ghc-text" ,ghc-text)))
@@ -4043,7 +3990,6 @@ representing a store for a single element.")
        (sha256
         (base32 "0vmmlsj8ggbpwx6fkf5fvb6jp0zpx6iba6b28m80lllr2p8bi8wm"))))
     (build-system haskell-build-system)
-    (inputs `(("ghc-mtl" ,ghc-mtl)))
     (home-page "http://rwd.rdockins.name/edison/home/")
     (synopsis "Library of efficient, purely-functional data structures (API)")
     (description
@@ -4069,8 +4015,7 @@ finite maps and priority queues where the priority and element are distinct.")
         (base32 "06shxmcqxcahcn6zgl64vlqix4fnq53d97drcgsh94qp7gp201ry"))))
     (build-system haskell-build-system)
     (inputs
-     `(("ghc-mtl" ,ghc-mtl)
+     `(("ghc-quickcheck" ,ghc-quickcheck)
-       ("ghc-quickcheck" ,ghc-quickcheck)
        ("ghc-edisonapi" ,ghc-edisonapi)))
     (home-page "http://rwd.rdockins.name/edison/home/")
     (synopsis "Library of efficient, purely-functional data structures")
@@ -4096,8 +4041,7 @@ with various performance characteristics.")
          "1i8dzrc5qi3ryc9vrrmpn3sihmramsbhhd592w4w2k5g26qr3hql"))))
     (build-system haskell-build-system)
     (inputs
-     `(("ghc-mtl" ,ghc-mtl)
+     `(("ghc-transformers-compat" ,ghc-transformers-compat)))
-       ("ghc-transformers-compat" ,ghc-transformers-compat)))
     (home-page "https://hackage.haskell.org/package/mmorph")
     (synopsis "Monad morphisms")
     (description
@@ -4118,7 +4062,6 @@ manipulating monad transformer stacks.")
         (base32
          "1kfx1bwfjczj93a8yqz1n8snqiq5655qgzwv1lrycry8wb1vzlwa"))))
     (build-system haskell-build-system)
-    (inputs `(("ghc-mtl" ,ghc-mtl)))
     (home-page "http://hackage.haskell.org/package/IfElse")
     (synopsis "Monadic control flow with anaphoric variants")
     (description "This library provides functions for control flow inside of
@@ -4638,7 +4581,6 @@ given term should not exist.")
        ("ghc-contravariant" ,ghc-contravariant)
        ("ghc-distributive" ,ghc-distributive)
        ("ghc-free" ,ghc-free)
-       ("ghc-mtl" ,ghc-mtl)
        ("ghc-semigroupoids" ,ghc-semigroupoids)
        ("ghc-tagged" ,ghc-tagged)))
     (home-page "https://github.com/ekmett/kan-extensions/")
@@ -4728,7 +4670,6 @@ in the @code{IO} monad, like @code{IORef}s or parts of the OpenGL state.")
        ("ghc-comonad" ,ghc-comonad)
        ("ghc-contravariant" ,ghc-contravariant)
        ("ghc-hashable" ,ghc-hashable)
-       ("ghc-mtl" ,ghc-mtl)
        ("ghc-profunctors" ,ghc-profunctors)
        ("ghc-semigroups" ,ghc-semigroups)
        ("ghc-tagged" ,ghc-tagged)
@@ -4772,8 +4713,7 @@ indexed variants.")
          "1hiqi7h76shjzs2zj0j8g6wnq2hbiq1hmfafdazr97fba2zl2432"))))
     (build-system haskell-build-system)
     (inputs
-     `(("ghc-mtl" ,ghc-mtl)
+     `(("ghc-text" ,ghc-text)
-       ("ghc-text" ,ghc-text)
        ("ghc-blaze-html" ,ghc-blaze-html)
        ("ghc-xss-sanitize" ,ghc-xss-sanitize)
        ("ghc-data-default" ,ghc-data-default)
@@ -4936,7 +4876,6 @@ semigroup.")
        ("ghc-bifunctors" ,ghc-bifunctors)
        ("ghc-comonad" ,ghc-comonad)
        ("ghc-distributive" ,ghc-distributive)
-       ("ghc-mtl" ,ghc-mtl)
        ("ghc-semigroupoids" ,ghc-semigroupoids)
        ("ghc-semigroups" ,ghc-semigroups)))
     (home-page "https://github.com/ekmett/free/")
@@ -4971,7 +4910,6 @@ definition of @code{Monad}.")
        ("ghc-contravariant" ,ghc-contravariant)
        ("ghc-distributive" ,ghc-distributive)
        ("ghc-free" ,ghc-free)
-       ("ghc-mtl" ,ghc-mtl)
        ("ghc-tagged" ,ghc-tagged)
        ("ghc-semigroupoids" ,ghc-semigroupoids)
        ("ghc-semigroups" ,ghc-semigroups)
@@ -4995,8 +4933,7 @@ for Haskell.")
         (base32 "0a85bdyyvjqs5z4kfhhf758210k9gi9dv42ik66a3jl0z7aix8kx"))))
     (build-system haskell-build-system)
     (inputs
-     `(("ghc-mtl" ,ghc-mtl)
+     `(("ghc-stmonadtrans" ,ghc-stmonadtrans)
-       ("ghc-stmonadtrans" ,ghc-stmonadtrans)
        ("ghc-transformers-compat" ,ghc-transformers-compat)
        ("ghc-quickcheck" ,ghc-quickcheck)
        ("ghc-test-framework" ,ghc-test-framework)
@@ -5393,7 +5330,6 @@ building up, manipulating and serialising @code{Pandoc} structures.")
        ("ghc-utf8-string" ,ghc-utf8-string)
        ("ghc-xml" ,ghc-xml)
        ("ghc-parsec" ,ghc-parsec)
-       ("ghc-mtl" ,ghc-mtl)
        ("ghc-pandoc-types" ,ghc-pandoc-types)))
     (home-page "https://github.com/jgm/texmath")
     (synopsis "Conversion between formats used to represent mathematics")
@@ -5417,8 +5353,7 @@ it can parse and apply LaTeX macros.")
                (base32
                 "129q33m56diiv35kdwfb07838wrg0mm88kxdqxfyl1zvf9nzkqkd"))))
     (inputs
-     `(("ghc-mtl" ,ghc-mtl)
+     `(("ghc-network-uri" ,ghc-network-uri)
-       ("ghc-network-uri" ,ghc-network-uri)
        ("ghc-pandoc-types" ,ghc-pandoc-types-for-pandoc-1)
        ("ghc-parsec" ,ghc-parsec)
        ("ghc-split" ,ghc-split)
@@ -5492,8 +5427,7 @@ and utilities for pretty printing.")
     (native-inputs
      `(("ghc-parsec" ,ghc-parsec)
        ("ghc-blaze-html" ,ghc-blaze-html)
-       ("ghc-utf8-string" ,ghc-utf8-string)
+       ("ghc-utf8-string" ,ghc-utf8-string)))
-       ("ghc-mtl" ,ghc-mtl)))
     (home-page "https://github.com/jgm/highlighting-kate")
     (synopsis "Syntax highlighting library")
     (description
@@ -5747,8 +5681,7 @@ instances.  This package provides orphan instances for @code{containers},
                 "1b76zjxkj0v0n8zj9l0nwav2irm0c43rx6qjihfw8klmmxvx59df"))))
     (build-system haskell-build-system)
     (inputs
-     `(("ghc-mtl" ,ghc-mtl)
+     `(("ghc-safe" ,ghc-safe)
-       ("ghc-safe" ,ghc-safe)
        ("ghc-th-expand-syns" ,ghc-th-expand-syns)))
     (home-page "https://github.com/mgsloan/th-reify-many")
     (synopsis "Recurseively reify template haskell datatype info")
@@ -5775,7 +5708,6 @@ function which generates instances.")
      `(("ghc-th-lift" ,ghc-th-lift)
        ("ghc-th-lift-instances" ,ghc-th-lift-instances)
        ("ghc-th-reify-many" ,ghc-th-reify-many)
-       ("ghc-mtl" ,ghc-mtl)
        ("ghc-generic-deriving" ,ghc-generic-deriving)))
     (native-inputs
      `(("ghc-hspec" ,ghc-hspec)))
@@ -5801,7 +5733,6 @@ package, and that's where the version number started.")
        (sha256
         (base32 "17vjps2118s5z3k39ij00lkmkxv3mqf8h59wv6qdamlgmhyr36si"))))
     (build-system haskell-build-system)
-    (inputs `(("ghc-mtl" ,ghc-mtl)))
     (home-page "https://github.com/danr/geniplate")
     (synopsis "Use Template Haskell to generate Uniplate-like functions")
     (description
@@ -5877,7 +5808,6 @@ template-haskell abstract syntax.")
        ("ghc-lifted-base" ,ghc-lifted-base)
        ("ghc-mono-traversable" ,ghc-mono-traversable)
        ("ghc-mmorph" ,ghc-mmorph)
-       ("ghc-mtl" ,ghc-mtl)
        ("ghc-resourcet" ,ghc-resourcet)
        ("ghc-silently" ,ghc-silently)
        ("ghc-transformers-base" ,ghc-transformers-base)
@@ -6003,8 +5933,7 @@ back-ends.")
                 "0ilqr8jv41zxcj5qyicg29m8s30b9v70x6f9h2h2rw5ap8bxldl8"))))
     (build-system haskell-build-system)
     (inputs
-     `(("ghc-mtl" ,ghc-mtl)
+     `(("ghc-unix-compat" ,ghc-unix-compat)))
-       ("ghc-unix-compat" ,ghc-unix-compat)))
     (home-page "https://github.com/bos/filemanip")
     (synopsis "File and directory manipulation for Haskell")
     (description
@@ -6048,8 +5977,7 @@ do on-demand loading.")
                 "14s57fgf6kd5n5al2kcvk1aaxbq1ph0r5h8blflrjkx83yl6r8yn"))))
     (build-system haskell-build-system)
     (inputs
-     `(("ghc-mtl" ,ghc-mtl)
+     `(("ghc-zlib" ,ghc-zlib)
-       ("ghc-zlib" ,ghc-zlib)
        ("ghc-vector" ,ghc-vector)
        ("ghc-primitive" ,ghc-primitive)
        ("ghc-mmap" ,ghc-mmap)))
@@ -6078,7 +6006,6 @@ TIFF and GIF formats.")
      `(("lua" ,lua)
        ("ghc-exceptions" ,ghc-exceptions)
        ("ghc-fail" ,ghc-fail)
-       ("ghc-mtl" ,ghc-mtl)
        ("ghc-text" ,ghc-text)))
     (native-inputs
      `(("ghc-tasty" ,ghc-tasty)
@@ -6176,8 +6103,7 @@ wrapping a bytestring with stronger and more meaniful name.")
                 "104d1yd84hclprg740nkz60vx589mnm094zriw6zczbgg8nkclym"))))
     (build-system haskell-build-system)
     (inputs
-     `(("ghc-mtl" ,ghc-mtl)
+     `(("ghc-old-locale" ,ghc-old-locale)))
-       ("ghc-old-locale" ,ghc-old-locale)))
     (native-inputs
      `(("ghc-tasty" ,ghc-tasty)
        ("ghc-tasty-quickcheck" ,ghc-tasty-quickcheck)
@@ -6322,7 +6248,6 @@ the choice of SSL/TLS, and SOCKS.")
        ("ghc-colour" ,ghc-colour)
        ("ghc-diff" ,ghc-diff)
        ("ghc-hxt" ,ghc-hxt)
-       ("ghc-mtl" ,ghc-mtl)
        ("ghc-pretty-show" ,ghc-pretty-show)
        ("ghc-regex-pcre-builtin" ,ghc-regex-pcre-builtin)
        ("ghc-safe" ,ghc-safe)
@@ -6388,7 +6313,6 @@ provided.  Skylighting is intended to be the successor to highlighting-kate.")
        ("ghc-case-insensitive" ,ghc-case-insensitive)
        ("ghc-diff" ,ghc-diff)
        ("ghc-hxt" ,ghc-hxt)
-       ("ghc-mtl" ,ghc-mtl)
        ("ghc-pretty-show" ,ghc-pretty-show)
        ("ghc-regex-pcre-builtin" ,ghc-regex-pcre-builtin)
        ("ghc-safe" ,ghc-safe)
@@ -6483,7 +6407,6 @@ provided.  Skylighting is intended to be the successor to highlighting-kate.")
        ("ghc-http-client-tls" ,ghc-http-client-tls)
        ("ghc-http-types" ,ghc-http-types)
        ("ghc-juicypixels" ,ghc-juicypixels)
-       ("ghc-mtl" ,ghc-mtl)
        ("ghc-network" ,ghc-network)
        ("ghc-network-uri" ,ghc-network-uri)
        ("ghc-old-locale" ,ghc-old-locale)
@@ -6560,7 +6483,6 @@ provided for those who need a drop-in replacement for Markdown.pl.")
        ("ghc-http-client-tls" ,ghc-http-client-tls)
        ("ghc-http-types" ,ghc-http-types)
        ("ghc-juicypixels" ,ghc-juicypixels)
-       ("ghc-mtl" ,ghc-mtl)
        ("ghc-network" ,ghc-network)
        ("ghc-network-uri" ,ghc-network-uri)
        ("ghc-old-time" ,ghc-old-time)
@@ -6782,8 +6704,7 @@ the @code{conduit} package.")
          (add-after 'install 'post-install-check
            (assoc-ref %standard-phases 'check)))))
     (inputs
-     `(("ghc-mtl" ,ghc-mtl)
+     `(("ghc-pandoc-types" ,ghc-pandoc-types)
-       ("ghc-pandoc-types" ,ghc-pandoc-types)
        ("ghc-pandoc" ,ghc-pandoc)
        ("ghc-tagsoup" ,ghc-tagsoup)
        ("ghc-aeson" ,ghc-aeson)
@@ -6935,8 +6856,7 @@ regular expressions.  Parsers can be built using Applicative interface.")
          "0f8x8wyr6m21g8dnxvnvalz5bsq37l125l6qhs0fscbvprsxc4nb"))))
     (build-system haskell-build-system)
     (inputs
-     `(("ghc-mtl" ,ghc-mtl)
+     `(("ghc-parsec" ,ghc-parsec)
-       ("ghc-parsec" ,ghc-parsec)
        ("ghc-regex-base" ,ghc-regex-base)))
     (home-page "https://github.com/ChrisKuklewicz/regex-tdfa")
     (synopsis "POSIX extended regular expressions in Haskell.")
@@ -7070,8 +6990,6 @@ an index.")
        (sha256
         (base32 "1nr26fnmi5fdjc6d00w13kjhmfyvb5b837d0006w4dj0yxndaksp"))))
     (build-system haskell-build-system)
-    (inputs
-     `(("ghc-mtl" ,ghc-mtl)))
     (home-page "https://hackage.haskell.org/package/STMonadTrans")
     (synopsis "Monad transformer version of the ST monad")
     (description
@@ -7288,7 +7206,6 @@ and edge labels with positional information, etc.
     (build-system haskell-build-system)
     (inputs
      `(("ghc-hashable" ,ghc-hashable)
-       ("ghc-mtl" ,ghc-mtl)
        ("ghc-transformers-compat" ,ghc-transformers-compat)))
     (home-page "https://github.com/ekmett/constraints/")
     (synopsis "Constraint manipulation")
@@ -7319,7 +7236,6 @@ a vocabulary for working with them.")
        ("ghc-monad-control" ,ghc-monad-control)
        ("ghc-constraints" ,ghc-constraints)
        ("ghc-hunit" ,ghc-hunit)
-       ("ghc-mtl" ,ghc-mtl)
        ("ghc-tasty" ,ghc-tasty)
        ("ghc-tasty-hunit" ,ghc-tasty-hunit)
        ("ghc-tasty-th" ,ghc-tasty-th)))
@@ -7408,8 +7324,7 @@ which can't be decoded in the current locale encoding.")
          "023fbvbqs5gdwm30j5517gbdcc7fvz0md70dgwgpypkskj3i926y"))))
     (build-system haskell-build-system)
     (inputs
-     `(("ghc-mtl" ,ghc-mtl)
+     `(("ghc-unix-compat" ,ghc-unix-compat)
-       ("ghc-unix-compat" ,ghc-unix-compat)
        ("ghc-system-filepath-bootstrap" ,ghc-system-filepath-bootstrap)
        ("ghc-system-fileio-bootstrap" ,ghc-system-fileio-bootstrap)
        ("ghc-monad-control" ,ghc-monad-control)
@@ -8102,8 +8017,7 @@ files in Haskell.")
                 "0as5gvlh6pi2gflakp695qnlizyyp059dqrhvjl4gjxalja6xjnp"))))
     (build-system haskell-build-system)
     (inputs
-     `(("ghc-mtl" ,ghc-mtl)
+     `(("ghc-network" ,ghc-network)
-       ("ghc-network" ,ghc-network)
        ("ghc-old-locale" ,ghc-old-locale)))
     (native-inputs
      `(("ghc-hunit" ,ghc-hunit)))
@@ -8148,7 +8062,6 @@ handled safely, this is what you're left with.")
     (build-system haskell-build-system)
     (inputs
      `(("ghc-syb" ,ghc-syb)
-       ("ghc-mtl" ,ghc-mtl)
        ("ghc-text" ,ghc-text)
        ("ghc-parsec" ,ghc-parsec)))
     (home-page "https://hackage.haskell.org/package/json")
@@ -8213,7 +8126,6 @@ generated SQL and optimize it for your backend.")
     (inputs
      `(("ghc-quickcheck" ,ghc-quickcheck)
        ("ghc-json" ,ghc-json)
-       ("ghc-mtl" ,ghc-mtl)
        ("ghc-parsec" ,ghc-parsec)
        ("ghc-regex-tdfa" ,ghc-regex-tdfa)))
     (home-page "https://github.com/koalaman/shellcheck")
@@ -8546,7 +8458,6 @@ between 2 and 3 times faster than the Mersenne Twister.")
              #t)))))
     (inputs
      `(("ghc-vector" ,ghc-vector)
-       ("ghc-mtl" ,ghc-mtl)
        ("ghc-mwc-random" ,ghc-mwc-random)))
     (native-inputs
      `(("ghc-quickcheck" ,ghc-quickcheck)))
@@ -8622,8 +8533,7 @@ module for more details.")
     (build-system haskell-build-system)
     (inputs `(("ghc-abstract-par" ,ghc-abstract-par)
               ("ghc-cereal" ,ghc-cereal)
-              ("ghc-random" ,ghc-random)
+              ("ghc-random" ,ghc-random)))
-              ("ghc-mtl" ,ghc-mtl)))
     (home-page "https://github.com/simonmar/monad-par")
     (synopsis "Combinators and extra features for Par monads for Haskell")
     (description "This Haskell package provides additional data structures,
@@ -8685,8 +8595,7 @@ This package also includes a simple reference implementation based on
               ("ghc-abstract-deque" ,ghc-abstract-deque)
               ("ghc-monad-par-extras" ,ghc-monad-par-extras)
               ("ghc-mwc-random" ,ghc-mwc-random)
-              ("ghc-parallel" ,ghc-parallel)
+              ("ghc-parallel" ,ghc-parallel)))
-              ("ghc-mtl" ,ghc-mtl)))
     (native-inputs `(("ghc-quickcheck" ,ghc-quickcheck)
                      ("ghc-hunit" ,ghc-hunit)
                      ("ghc-test-framework-hunit" ,ghc-test-framework-hunit)
@@ -8879,7 +8788,6 @@ statically known size.")
          "1h1nhswrcmhy3mq6vd530p0df51fcnnf4csbwnljar7cf0mb2h6y"))))
     (build-system haskell-build-system)
     (inputs `(("ghc-transformers-compat" ,ghc-transformers-compat)
-              ("ghc-mtl" ,ghc-mtl)
               ("ghc-primitive" ,ghc-primitive)
               ("ghc-fail" ,ghc-fail)
               ("ghc-random" ,ghc-random)))
@@ -8908,7 +8816,6 @@ which consume random values.")
               ("ghc-free" ,ghc-free)
               ("ghc-monad-control" ,ghc-monad-control)
               ("ghc-manodrandom" ,ghc-monadrandom)
-              ("ghc-mtl" ,ghc-mtl)
               ("ghc-mmorph" ,ghc-mmorph)
               ("ghc-profunctors" ,ghc-profunctors)
               ("ghc-semigroups" ,ghc-semigroups)
@@ -9057,7 +8964,6 @@ parsing and printing @dfn{Universally Unique Identifiers} or UUIDs.")
               ("ghc-contravariant" ,ghc-contravariant)
               ("ghc-contravariant-extras" ,ghc-contravariant-extras)
               ("ghc-semigroups" ,ghc-semigroups)
-              ("ghc-mtl" ,ghc-mtl)
               ("ghc-either" ,ghc-either)
               ("ghc-fail" ,ghc-fail)
               ("ghc-base-prelude" ,ghc-base-prelude)))
@@ -9219,7 +9125,6 @@ data structures as non-empty.")
               ("ghc-mono-traversable" ,ghc-mono-traversable)))
     (native-inputs `(("ghc-hspec" ,ghc-hspec)
                      ("ghc-silently" ,ghc-silently)
-                     ("ghc-mtl" ,ghc-mtl)
                      ("ghc-safe" ,ghc-safe)
                      ("ghc-quickcheck" ,ghc-quickcheck)))
     (home-page "https://github.com/snoyberg/mono-traversable")
@@ -9258,7 +9163,6 @@ as well as a convenient Conduit module.")
        ("ghc-http-conduit" ,ghc-http-conduit)
        ("ghc-http-types" ,ghc-http-types)
        ("ghc-monad-control" ,ghc-monad-control)
-       ("ghc-mtl" ,ghc-mtl)
        ("ghc-network" ,ghc-network)
        ("ghc-old-locale" ,ghc-old-locale)
        ("ghc-safe" ,ghc-safe)
@@ -9411,7 +9315,6 @@ operators for looping.")
               ("ghc-transformers-base" ,ghc-transformers-base)
               ("ghc-monad-control" ,ghc-monad-control)
               ("ghc-monad-loops" ,ghc-monad-loops)
-              ("ghc-mtl" ,ghc-mtl)
               ("ghc-blaze-builder" ,ghc-blaze-builder)
               ("ghc-exceptions" ,ghc-exceptions)))
     (home-page "https://github.com/kazu-yamamoto/logger")
@@ -9652,7 +9555,6 @@ Haskell data types to and from HTTP API data.")
               ("ghc-blaze-html" ,ghc-blaze-html)
               ("ghc-blaze-markup" ,ghc-blaze-markup)
               ("ghc-silently" ,ghc-silently)
-              ("ghc-mtl" ,ghc-mtl)
               ("ghc-fast-logger" ,ghc-fast-logger)
               ("ghc-scientific" ,ghc-scientific)
               ("ghc-tagged" ,ghc-tagged)))
@@ -9932,7 +9834,6 @@ address string against RFC 5322.")
    (inputs `(("ghc-cereal" ,ghc-cereal)
              ("cabal-doctest" ,cabal-doctest)
              ("ghc-doctest" ,ghc-doctest-0.13)
-             ("ghc-mtl" ,ghc-mtl)
              ("ghc-scientific" ,ghc-scientific)
              ("ghc-text" ,ghc-text)
              ("ghc-transformers-compat" ,ghc-transformers-compat)
@@ -10032,7 +9933,6 @@ This package provides an orphan instance.")
     (inputs
      `(("ghc-network" ,ghc-network)
        ("ghc-parsec" ,ghc-parsec)
-       ("ghc-mtl" ,ghc-mtl)
        ("ghc-hunit" ,ghc-hunit)
        ("ghc-regex-compat" ,ghc-regex-compat)
        ("ghc-hslogger" ,ghc-hslogger)
@@ -10088,8 +9988,7 @@ example code on the home page for a quick introduction.")
          "1x2abg2q9d26h1vzj40r6k7k3gqgappbs4g9d853vvg77837km4i"))))
     (build-system haskell-build-system)
     (inputs
-     `(("ghc-mtl" ,ghc-mtl)
+     `(("ghc-random" ,ghc-random)))
-       ("ghc-random" ,ghc-random)))
     (home-page "http://wiki.haskell.org/Operational")
     (synopsis "Implementation of difficult monads made easy with operational semantics")
     (description
@@ -10146,7 +10045,6 @@ tools are not needed to actually run Gtk2Hs programs.")
     (build-system haskell-build-system)
     (inputs
      `(("ghc-old-locale" ,ghc-old-locale)
-       ("ghc-mtl" ,ghc-mtl)
        ("ghc-lens" ,ghc-lens)
        ("ghc-colour" ,ghc-colour)
        ("ghc-data-default-class" ,ghc-data-default-class)

gnu/packages/idris.scm

@@ -106,7 +106,6 @@
        ("ghc-fingertree" ,ghc-fingertree)
        ("ghc-fsnotify" ,ghc-fsnotify)
        ("ghc-ieee754" ,ghc-ieee754)
-       ("ghc-mtl" ,ghc-mtl)
        ("ghc-network" ,ghc-network)
        ("ghc-optparse-applicative" ,ghc-optparse-applicative)
        ("ghc-regex-tdfa" ,ghc-regex-tdfa)

gnu/packages/tls.scm

@@ -881,8 +881,7 @@ coding footprint.")
                 "1rdidf18i781c0vdvy9yn79yh08hmcacf6fp3sgghyiy3h0wyh5l"))))
     (build-system haskell-build-system)
     (inputs
-     `(("ghc-mtl" ,ghc-mtl)
+     `(("ghc-cereal" ,ghc-cereal)
-       ("ghc-cereal" ,ghc-cereal)
        ("ghc-data-default-class" ,ghc-data-default-class)
        ("ghc-memory" ,ghc-memory)
        ("ghc-cryptonite" ,ghc-cryptonite)

gnu/packages/version-control.scm

@@ -1895,7 +1895,6 @@ be served with a HTTP file server of your choice.")
        ("ghc-hashable" ,ghc-hashable)
        ("ghc-html" ,ghc-html)
        ("ghc-mmap" ,ghc-mmap)
-       ("ghc-mtl" ,ghc-mtl)
        ("ghc-old-time" ,ghc-old-time)
        ("ghc-parsec" ,ghc-parsec)
        ("ghc-random" ,ghc-random)
@@ -2188,7 +2187,6 @@ directory full of HOWTOs.")
        ("ghc-memory" ,ghc-memory)
        ("ghc-monad-control" ,ghc-monad-control)
        ("ghc-monad-logger" ,ghc-monad-logger)
-       ("ghc-mtl" ,ghc-mtl)
        ("ghc-network" ,ghc-network)
        ("ghc-old-locale" ,ghc-old-locale)
        ("ghc-optparse-applicative" ,ghc-optparse-applicative)

gnu/packages/wm.scm

@@ -467,7 +467,6 @@ desktop environment.")
     (build-system haskell-build-system)
     (inputs
      `(("ghc-extensible-exceptions" ,ghc-extensible-exceptions)
-       ("ghc-mtl"                   ,ghc-mtl)
        ("ghc-quickcheck"            ,ghc-quickcheck)
        ("ghc-semigroups"            ,ghc-semigroups)
        ("ghc-setlocale"             ,ghc-setlocale)
@@ -560,8 +559,7 @@ Haskell, no knowledge of the language is required to install and use it.")
          "1660w3xhbfrlq8b8s1rviq2mcn1vyqpypli4023gqxwry52brk6y"))))
     (build-system haskell-build-system)
     (propagated-inputs
-     `(("ghc-mtl" ,ghc-mtl)
+     `(("ghc-old-time" ,ghc-old-time)
-       ("ghc-old-time" ,ghc-old-time)
        ("ghc-random" ,ghc-random)
        ("ghc-utf8-string" ,ghc-utf8-string)
        ("ghc-extensible-exceptions" ,ghc-extensible-exceptions)

gnu/packages/xml.scm

@@ -2078,7 +2078,6 @@ derivations of regular expressions.")
     (build-system haskell-build-system)
     (inputs
      `(("ghc-parsec" ,ghc-parsec)
-       ("ghc-mtl" ,ghc-mtl)
        ("ghc-hxt-charproperties" ,ghc-hxt-charproperties)
        ("ghc-hxt-unicode" ,ghc-hxt-unicode)
        ("ghc-hxt-regex-xmlschema" ,ghc-hxt-regex-xmlschema)