diff --git a/gnu/packages/bioinformatics.scm b/gnu/packages/bioinformatics.scm
index 22bd81c75b..6a90aa9456 100644
--- a/gnu/packages/bioinformatics.scm
+++ b/gnu/packages/bioinformatics.scm
@@ -2670,10 +2670,10 @@ the phenotype as it models the data.")
     (license license:asl2.0)))
 
 (define-public pbtranscript-tofu
-  (let ((commit "8f5467fe6"))
+  (let ((commit "8f5467fe6a4472bcfb4226c8720993c8507adfe4"))
     (package
       (name "pbtranscript-tofu")
-      (version (string-append "2.2.3." commit))
+      (version (string-append "2.2.3." (string-take commit 7)))
       (source (origin
                 (method git-fetch)
                 (uri (git-reference
@@ -3009,7 +3009,7 @@ viewer.")
                (delete 'configure))))))))
 
 (define-public mosaik
-  (let ((commit "5c25216d"))
+  (let ((commit "5c25216d3522d6a33e53875cd76a6d65001e4e67"))
     (package
       (name "mosaik")
       (version "2.2.30")
@@ -3259,10 +3259,10 @@ subsequent visualization, annotation and storage of results.")
 
 (define-public smithlab-cpp
   (let ((revision "1")
-        (commit "728a097"))
+        (commit "728a097bec88c6f4b8528b685932049e660eff2e"))
     (package
       (name "smithlab-cpp")
-      (version (string-append "0." revision "." commit))
+      (version (string-append "0." revision "." (string-take commit 7)))
       (source (origin
                 (method git-fetch)
                 (uri (git-reference
@@ -5169,7 +5169,7 @@ libraries for systems that do not have these available via other means.")
        ("samtools" ,samtools-0.1)
        ("gsl" ,gsl)
        ("smithlab-cpp"
-        ,(let ((commit "3723e2d"))
+        ,(let ((commit "3723e2db438c51501d0423429ff396c3035ba46a"))
            (origin
              (method git-fetch)
              (uri (git-reference
diff --git a/gnu/packages/ci.scm b/gnu/packages/ci.scm
index be18ebd29f..e0ff873b3e 100644
--- a/gnu/packages/ci.scm
+++ b/gnu/packages/ci.scm
@@ -39,10 +39,10 @@
   #:use-module (guix build-system gnu))
 
 (define-public hydra
-  (let ((commit "4c0e3e4"))
+  (let ((commit "4c0e3e47034545ad3e9e86dd069138bcebb8ccee"))
     (package
       (name "hydra")
-      (version (string-append "20150407." commit))
+      (version (string-append "20150407." (string-take commit 7)))
       (source (origin
                 (method git-fetch)
                 (uri (git-reference
diff --git a/gnu/packages/compression.scm b/gnu/packages/compression.scm
index 5746ca3e03..dd107487fb 100644
--- a/gnu/packages/compression.scm
+++ b/gnu/packages/compression.scm
@@ -443,16 +443,17 @@ with the sfArk algorithm.")
     (license license:gpl3+)))
 
 (define-public sfarkxtc
+ (let ((commit "b5e0a2ba3921f019d74d4b92bd31c36dd19d2cf1"))
   (package
     (name "sfarkxtc")
-    (version "b5e0a2ba39")
+    (version (string-take commit 10))
     (source (origin
               ;; There are no release tarballs, so we just fetch the latest
               ;; commit at this time.
               (method git-fetch)
               (uri (git-reference
                     (url "https://github.com/raboof/sfarkxtc.git")
-                    (commit version)))
+                    (commit commit)))
               (sha256
                (base32
                 "0f5x6i46qfl6ry21s7g2p4sd4b2r1g4fb03yqi2vv4kq3saryhvj"))))
@@ -473,7 +474,7 @@ with the sfArk algorithm.")
     (synopsis "Basic sfArk decompressor")
     (description "SfArk extractor converts SoundFonts in the compressed legacy
 sfArk file format to the uncompressed sf2 format.")
-    (license license:gpl3+)))
+    (license license:gpl3+))))
 
 (define-public libmspack
   (package
diff --git a/gnu/packages/emacs.scm b/gnu/packages/emacs.scm
index 797041f05d..07b4255adb 100644
--- a/gnu/packages/emacs.scm
+++ b/gnu/packages/emacs.scm
@@ -1238,7 +1238,7 @@ files and directories.")
     (source (origin
               (method git-fetch)
               (uri (git-reference
-                    (commit "8807064693")
+                    (commit "880706469338ab59b5bb7dbe8460016f89755364")
                     (url "https://github.com/gregsexton/ob-ipython.git")))
               (sha256
                (base32
diff --git a/gnu/packages/games.scm b/gnu/packages/games.scm
index e552d09efa..368f09632c 100644
--- a/gnu/packages/games.scm
+++ b/gnu/packages/games.scm
@@ -590,11 +590,11 @@ for common mesh file formats, and collision detection.")
   ;; The latest release on SourceForge relies on an unreleased version of SFML
   ;; with a different API, so we take the latest version from the official
   ;; repository on Github.
-  (let ((commit   "c855d04409")
+  (let ((commit   "c855d044094a1d92317e38935d81ba938946132e")
         (revision "1"))
     (package
       (name "mars")
-      (version (string-append "0.7.5." revision "." commit ))
+      (version (string-append "0.7.5." revision "." (string-take commit 7) ))
       (source (origin
                 (method git-fetch)
                 (uri (git-reference
@@ -1833,36 +1833,37 @@ emulation community.  It provides highly accurate emulation.")
     (license license:gpl2+)))
 
 (define-public emulation-station
-  (package
-    (name "emulation-station")
-    (version "2.0.1")
-    (source (origin
-              (method git-fetch) ; no tarball available
-              (uri (git-reference
-                    (url "https://github.com/Aloshi/EmulationStation.git")
-                    (commit "646bede"))) ; no version tag
-              (sha256
-               (base32
-                "0cm0sq2wri2l9cvab1l0g02za59q7klj0h3p028vr96n6njj4w9v"))))
-    (build-system cmake-build-system)
-    (arguments
-     '(#:tests? #f)) ; no tests
-    (inputs
-     `(("alsa-lib" ,alsa-lib)
-       ("boost" ,boost)
-       ("curl" ,curl)
-       ("eigin" ,eigen)
-       ("freeimage" ,freeimage)
-       ("freetype" ,freetype)
-       ("mesa" ,mesa)
-       ("sdl2" ,sdl2)))
-    (synopsis "Video game console emulator front-end")
-    (description "EmulationStation provides a graphical front-end to a large
+  (let ((commit "646bede3d9ec0acf0ae378415edac136774a66c5"))
+    (package
+      (name "emulation-station")
+      (version "2.0.1")
+      (source (origin
+                (method git-fetch) ; no tarball available
+                (uri (git-reference
+                      (url "https://github.com/Aloshi/EmulationStation.git")
+                      (commit commit))) ; no version tag
+                (sha256
+                 (base32
+                  "0cm0sq2wri2l9cvab1l0g02za59q7klj0h3p028vr96n6njj4w9v"))))
+      (build-system cmake-build-system)
+      (arguments
+       '(#:tests? #f)) ; no tests
+      (inputs
+       `(("alsa-lib" ,alsa-lib)
+         ("boost" ,boost)
+         ("curl" ,curl)
+         ("eigin" ,eigen)
+         ("freeimage" ,freeimage)
+         ("freetype" ,freetype)
+         ("mesa" ,mesa)
+         ("sdl2" ,sdl2)))
+      (synopsis "Video game console emulator front-end")
+      (description "EmulationStation provides a graphical front-end to a large
 number of video game console emulators.  It features an interface that is
 usable with any game controller that has at least 4 buttons, theming support,
 and a game metadata scraper.")
-    (home-page "http://www.emulationstation.org")
-    (license license:expat)))
+      (home-page "http://www.emulationstation.org")
+      (license license:expat))))
 
 (define openttd-engine
   (package
diff --git a/gnu/packages/gnunet.scm b/gnu/packages/gnunet.scm
index b5a2685f65..0819c485cb 100644
--- a/gnu/packages/gnunet.scm
+++ b/gnu/packages/gnunet.scm
@@ -266,10 +266,10 @@ privacy-preserving, decentralized public key infrastructure.")
    (home-page "https://gnunet.org/")))
 
 (define-public guile-gnunet                       ;GSoC 2015!
-  (let ((commit "383eac2"))
+  (let ((commit "383eac2aab175d8d9ea5315c2f1c8a5055c76a52"))
     (package
       (name "guile-gnunet")
-      (version (string-append "0.0." commit))
+      (version (string-append "0.0." (string-take commit 7)))
       (source (origin
                 (method git-fetch)
                 (uri (git-reference
diff --git a/gnu/packages/music.scm b/gnu/packages/music.scm
index 50f9a70810..d491aa605e 100644
--- a/gnu/packages/music.scm
+++ b/gnu/packages/music.scm
@@ -437,10 +437,10 @@ Guile.")
 (define-public non-sequencer
   ;; The latest tagged release is three years old and uses a custom build
   ;; system, so we take the last commit affecting the "sequencer" directory.
-  (let ((commit "1d9bd576"))
+  (let ((commit "1d9bd576f6bf7ea240af5f7a60260592750af0dd"))
     (package
       (name "non-sequencer")
-      (version (string-append "1.9.5-" commit))
+      (version (string-append "1.9.5-" (string-take commit 7)))
       (source (origin
                 (method git-fetch)
                 (uri (git-reference
diff --git a/gnu/packages/version-control.scm b/gnu/packages/version-control.scm
index 26cd11acde..346f9753a8 100644
--- a/gnu/packages/version-control.scm
+++ b/gnu/packages/version-control.scm
@@ -479,7 +479,7 @@ will work.")
               (method git-fetch)
               (uri (git-reference
                     (url "https://github.com/nvie/gitflow/")
-                    (commit "15aab26")))
+                    (commit "15aab26490facf285acef56cb5d61025eacb3a69")))
               (sha256
                (base32
                 "01fs97q76fdfnvmrh2cyjhywcs3pykf1dg58sy0frflnsdzs6prx"))))
@@ -513,10 +513,10 @@ lot easier.")
     (license bsd-2)))
 
 (define-public git-test-sequence
-  (let ((commit "48e5a2f"))
+  (let ((commit "48e5a2f5a13a5f30452647237e23362b459b9c76"))
     (package
       (name "git-test-sequence")
-      (version (string-append "20140312." commit))
+      (version (string-append "20140312." (string-take commit 7)))
       (source (origin
                 (method git-fetch)
                 (uri (git-reference
diff --git a/gnu/packages/xorg.scm b/gnu/packages/xorg.scm
index fd933e36a7..46f0f6ec99 100644
--- a/gnu/packages/xorg.scm
+++ b/gnu/packages/xorg.scm
@@ -2810,10 +2810,10 @@ X server.")
 
 
 (define-public xf86-video-intel
-  (let ((commit "d167280"))
+  (let ((commit "d1672806a5222f00dcc2eb24ccddd03f727f71bc"))
     (package
       (name "xf86-video-intel")
-      (version (string-append "2.99.917-1-" commit))
+      (version (string-append "2.99.917-1-" (string-take commit 7)))
       (source
        (origin
          ;; there's no current tarball