diff --git a/gnu/packages/gcc.scm b/gnu/packages/gcc.scm
index aed2e8925e..938c38e670 100644
--- a/gnu/packages/gcc.scm
+++ b/gnu/packages/gcc.scm
@@ -281,10 +281,13 @@ Go.  It also includes runtime support libraries for these languages.")
               (base32
                "0zki3ngi0gsidnmsp88mjl2868cc7cm5wm1vwqw6znja28d7hd6k"))))))
 
-(define (custom-gcc gcc name languages)
+(define* (custom-gcc gcc name languages #:key (separate-lib-output? #t))
   "Return a custom version of GCC that supports LANGUAGES."
   (package (inherit gcc)
     (name name)
+    (outputs (if separate-lib-output?
+                 (package-outputs gcc)
+                 (delete "lib" (package-outputs gcc))))
     (arguments
      (substitute-keyword-arguments `(#:modules ((guix build gnu-build-system)
                                                 (guix build utils)
@@ -302,7 +305,11 @@ Go.  It also includes runtime support libraries for these languages.")
   (custom-gcc gcc-4.8 "gfortran" '("fortran")))
 
 (define-public gccgo-4.8
-  (custom-gcc gcc-4.8 "gccgo" '("go")))
+  (custom-gcc gcc-4.8 "gccgo" '("go")
+              ;; Suppress the separate "lib" output, because otherwise the
+              ;; "lib" and "out" outputs would refer to each other, creating
+              ;; a cyclic dependency.  <http://debbugs.gnu.org/18101>
+              #:separate-lib-output? #f))
 
 (define-public gcc-objc-4.8
   (custom-gcc gcc-4.8 "gcc-objc" '("objc")))
diff --git a/gnu/packages/gdb.scm b/gnu/packages/gdb.scm
index 1b8a0bbe22..b8d622e89d 100644
--- a/gnu/packages/gdb.scm
+++ b/gnu/packages/gdb.scm
@@ -24,7 +24,9 @@
   #:use-module (gnu packages texinfo)
   #:use-module (gnu packages multiprecision)
   #:use-module (gnu packages xml)
+  #:use-module (gnu packages guile)
   #:use-module (gnu packages python)
+  #:use-module (gnu packages pkg-config)
   #:use-module ((guix licenses) #:select (gpl3+))
   #:use-module (guix packages)
   #:use-module (guix download)
@@ -33,14 +35,14 @@
 (define-public gdb
   (package
     (name "gdb")
-    (version "7.7.1")
+    (version "7.8")
     (source (origin
              (method url-fetch)
              (uri (string-append "mirror://gnu/gdb/gdb-"
-                                 version ".tar.bz2"))
+                                 version ".tar.xz"))
              (sha256
               (base32
-               "199sn1p0gzli6icp9dcvrphdvyi7hm4cc9zhziq0q6vg81h55g8d"))))
+               "0xdqxjj77q60k19hn85msnbv9nchnpzi0lp7z7hm97zpfkhspi29"))))
     (build-system gnu-build-system)
     (arguments
      '(#:tests? #f ; FIXME "make check" fails on single-processor systems.
@@ -56,14 +58,17 @@
        ("gmp" ,gmp)
        ("readline" ,readline)
        ("ncurses" ,ncurses)
-       ("python" ,python-wrapper)
+       ("guile" ,guile-2.0)
+       ("python" ,python)
+       ("python-wrapper" ,python-wrapper)
        ("dejagnu" ,dejagnu)
 
        ;; Allow use of XML-formatted syscall information.  This enables 'catch
        ;; syscall' and similar commands.
        ("libxml2" ,libxml2)))
     (native-inputs
-      `(("texinfo" ,texinfo)))
+      `(("texinfo" ,texinfo)
+        ("pkg-config" ,pkg-config)))
     (home-page "http://www.gnu.org/software/gdb/")
     (synopsis "The GNU debugger")
     (description
diff --git a/gnu/packages/linux.scm b/gnu/packages/linux.scm
index 3ffe2a4cdd..105a8cb5c6 100644
--- a/gnu/packages/linux.scm
+++ b/gnu/packages/linux.scm
@@ -186,7 +186,7 @@ for SYSTEM, or #f if there is no configuration for SYSTEM."
      #f)))
 
 (define-public linux-libre
-  (let* ((version "3.15.6")
+  (let* ((version "3.15.8")
          (build-phase
           '(lambda* (#:key system inputs #:allow-other-keys #:rest args)
              ;; Apply the neat patch.
@@ -259,7 +259,7 @@ for SYSTEM, or #f if there is no configuration for SYSTEM."
              (uri (linux-libre-urls version))
              (sha256
               (base32
-               "07v45q8r9fz9jgj1m7dibbmcdlzfzpcj7kh2bp1s1pv512h7fnw0"))))
+               "1ichq7b08rrfq61i8kpan9vxw9mxcfpcl8cw0a6lbc1ycwzvm7xw"))))
     (build-system gnu-build-system)
     (native-inputs `(("perl" ,perl)
                      ("bc" ,bc)