bug#25414: address@hidden does not build deterministically

[Ludovic Courtès]

--8<---------------cut here---------------start------------->8---
address@hidden ~/src/guix$ ./pre-inst-env  guix challenge gdk-pixbuf 
--substitute-urls="https://mirror.hydra.gnu.org https://bayfront.guixsd.org";
updating list of substitutes from 'https://mirror.hydra.gnu.org'... 100.0%
updating list of substitutes from 'https://bayfront.guixsd.org'... 100.0%
guix challenge: warning: no local build for 
'/gnu/store/m4ccn9nzlsbvlj36w45555pq98spy007-gdk-pixbuf-2.34.0'
/gnu/store/m4ccn9nzlsbvlj36w45555pq98spy007-gdk-pixbuf-2.34.0 contents differ:
guix challenge: warning: no local build for 
'/gnu/store/m4ccn9nzlsbvlj36w45555pq98spy007-gdk-pixbuf-2.34.0'
  
https://mirror.hydra.gnu.org/nar/m4ccn9nzlsbvlj36w45555pq98spy007-gdk-pixbuf-2.34.0:
 1dw8mpw2i5fvvcxsc24dzqqjw43b1rgy2k25ad3z0iahdpq62sdh
  
https://bayfront.guixsd.org/nar/gzip/m4ccn9nzlsbvlj36w45555pq98spy007-gdk-pixbuf-2.34.0:
 0h4ff59hjn0libzzm1gvgk0zd0z5r834hfg5n0r61z5m6l6z0x40
address@hidden ~/src/guix$ wget -q -O -  
https://mirror.hydra.gnu.org/nar/m4ccn9nzlsbvlj36w45555pq98spy007-gdk-pixbuf-2.34.0
 | bunzip2 | guix archive -x /tmp/one
address@hidden ~/src/guix$ wget -q -O - 
https://bayfront.guixsd.org/nar/gzip/m4ccn9nzlsbvlj36w45555pq98spy007-gdk-pixbuf-2.34.0|
 gunzip | guix archive -x /tmp/two
address@hidden ~/src/guix$ diff -ur /tmp/{one,two}
diff -ur /tmp/one/lib/gdk-pixbuf-2.0/2.10.0/loaders.cache 
/tmp/two/lib/gdk-pixbuf-2.0/2.10.0/loaders.cache
--- /tmp/one/lib/gdk-pixbuf-2.0/2.10.0/loaders.cache    2017-01-11 
00:01:02.297133246 +0100
+++ /tmp/two/lib/gdk-pixbuf-2.0/2.10.0/loaders.cache    2017-01-11 
00:01:21.092971961 +0100
@@ -4,24 +4,11 @@
 #
 # LoaderDir = 
/gnu/store/m4ccn9nzlsbvlj36w45555pq98spy007-gdk-pixbuf-2.34.0/lib/gdk-pixbuf-2.0/2.10.0/loaders
 #
-"/gnu/store/m4ccn9nzlsbvlj36w45555pq98spy007-gdk-pixbuf-2.34.0/lib/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-jpeg.so"
-"jpeg" 5 "gdk-pixbuf" "JPEG" "LGPL"
-"image/jpeg" ""
-"jpeg" "jpe" "jpg" ""
-"\377\330" "" 100
-
-"/gnu/store/m4ccn9nzlsbvlj36w45555pq98spy007-gdk-pixbuf-2.34.0/lib/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-icns.so"
-"icns" 4 "gdk-pixbuf" "MacOS X icon" "GPL"
-"image/x-icns" ""
-"icns" ""
-"icns" "" 100
-
-"/gnu/store/m4ccn9nzlsbvlj36w45555pq98spy007-gdk-pixbuf-2.34.0/lib/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-qtif.so"
-"qtif" 4 "gdk-pixbuf" "QuickTime" "LGPL"
-"image/x-quicktime" "image/qtif" ""
-"qtif" "qif" ""
-"abcdidsc" "xxxx    " 100
-"abcdidat" "xxxx    " 100
+"/gnu/store/m4ccn9nzlsbvlj36w45555pq98spy007-gdk-pixbuf-2.34.0/lib/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-ani.so"
+"ani" 4 "gdk-pixbuf" "Windows animated cursor" "LGPL"
+"application/x-navi-animation" ""
+"ani" ""
+"RIFF    ACON" "    xxxx    " 100
 
 
"/gnu/store/m4ccn9nzlsbvlj36w45555pq98spy007-gdk-pixbuf-2.34.0/lib/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-gif.so"
 "gif" 4 "gdk-pixbuf" "GIF" "LGPL"
@@ -29,6 +16,38 @@
 "gif" ""
 "GIF8" "" 100
 
+"/gnu/store/m4ccn9nzlsbvlj36w45555pq98spy007-gdk-pixbuf-2.34.0/lib/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-ico.so"
+"ico" 5 "gdk-pixbuf" "Windows icon" "LGPL"
+"image/x-icon" "image/x-ico" "image/x-win-bitmap" "image/vnd.microsoft.icon" 
"application/ico" "image/ico" "image/icon" "text/ico" ""
+"ico" "cur" ""
+"  \001   " "zz znz" 100
+"  \002   " "zz znz" 100
+
+"/gnu/store/m4ccn9nzlsbvlj36w45555pq98spy007-gdk-pixbuf-2.34.0/lib/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-tiff.so"
+"tiff" 5 "gdk-pixbuf" "TIFF" "LGPL"
+"image/tiff" ""
+"tiff" "tif" ""
+"MM *" "  z " 100
+"II* " "   z" 100
+"II* \020   CR\002 " "   z zzz   z" 0
+
+"/gnu/store/m4ccn9nzlsbvlj36w45555pq98spy007-gdk-pixbuf-2.34.0/lib/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-pnm.so"
+"pnm" 4 "gdk-pixbuf" "PNM/PBM/PGM/PPM" "LGPL"
+"image/x-portable-anymap" "image/x-portable-bitmap" "image/x-portable-graymap" 
"image/x-portable-pixmap" ""
+"pnm" "pbm" "pgm" "ppm" ""
+"P1" "" 100
+"P2" "" 100
+"P3" "" 100
+"P4" "" 100
+"P5" "" 100
+"P6" "" 100
+
+"/gnu/store/m4ccn9nzlsbvlj36w45555pq98spy007-gdk-pixbuf-2.34.0/lib/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-bmp.so"
+"bmp" 5 "gdk-pixbuf" "BMP" "LGPL"
+"image/bmp" "image/x-bmp" "image/x-MS-bmp" ""
+"bmp" ""
+"BM" "" 100
+
 
"/gnu/store/m4ccn9nzlsbvlj36w45555pq98spy007-gdk-pixbuf-2.34.0/lib/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-xbm.so"
 "xbm" 4 "gdk-pixbuf" "XBM" "LGPL"
 "image/x-xbitmap" ""
@@ -36,11 +55,24 @@
 "#define " "" 100
 "/*" "" 50
 
-"/gnu/store/m4ccn9nzlsbvlj36w45555pq98spy007-gdk-pixbuf-2.34.0/lib/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-bmp.so"
-"bmp" 5 "gdk-pixbuf" "BMP" "LGPL"
-"image/bmp" "image/x-bmp" "image/x-MS-bmp" ""
-"bmp" ""
-"BM" "" 100
+"/gnu/store/m4ccn9nzlsbvlj36w45555pq98spy007-gdk-pixbuf-2.34.0/lib/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-jpeg.so"
+"jpeg" 5 "gdk-pixbuf" "JPEG" "LGPL"
+"image/jpeg" ""
+"jpeg" "jpe" "jpg" ""
+"\377\330" "" 100
+
+"/gnu/store/m4ccn9nzlsbvlj36w45555pq98spy007-gdk-pixbuf-2.34.0/lib/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-qtif.so"
+"qtif" 4 "gdk-pixbuf" "QuickTime" "LGPL"
+"image/x-quicktime" "image/qtif" ""
+"qtif" "qif" ""
+"abcdidsc" "xxxx    " 100
+"abcdidat" "xxxx    " 100
+
+"/gnu/store/m4ccn9nzlsbvlj36w45555pq98spy007-gdk-pixbuf-2.34.0/lib/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-icns.so"
+"icns" 4 "gdk-pixbuf" "MacOS X icon" "GPL"
+"image/x-icns" ""
+"icns" ""
+"icns" "" 100
 
 
"/gnu/store/m4ccn9nzlsbvlj36w45555pq98spy007-gdk-pixbuf-2.34.0/lib/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-xpm.so"
 "xpm" 4 "gdk-pixbuf" "XPM" "LGPL"
@@ -48,20 +80,6 @@
 "xpm" ""
 "/* XPM */" "" 100
 
-"/gnu/store/m4ccn9nzlsbvlj36w45555pq98spy007-gdk-pixbuf-2.34.0/lib/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-ani.so"
-"ani" 4 "gdk-pixbuf" "Windows animated cursor" "LGPL"
-"application/x-navi-animation" ""
-"ani" ""
-"RIFF    ACON" "    xxxx    " 100
-
-"/gnu/store/m4ccn9nzlsbvlj36w45555pq98spy007-gdk-pixbuf-2.34.0/lib/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-tiff.so"
-"tiff" 5 "gdk-pixbuf" "TIFF" "LGPL"
-"image/tiff" ""
-"tiff" "tif" ""
-"MM *" "  z " 100
-"II* " "   z" 100
-"II* \020   CR\002 " "   z zzz   z" 0
-
 
"/gnu/store/m4ccn9nzlsbvlj36w45555pq98spy007-gdk-pixbuf-2.34.0/lib/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-png.so"
 "png" 5 "gdk-pixbuf" "PNG" "LGPL"
 "image/png" ""
@@ -79,22 +97,4 @@
 "  \n" "xz " 100
 "  \v" "xz " 100
 
-"/gnu/store/m4ccn9nzlsbvlj36w45555pq98spy007-gdk-pixbuf-2.34.0/lib/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-ico.so"
-"ico" 5 "gdk-pixbuf" "Windows icon" "LGPL"
-"image/x-icon" "image/x-ico" "image/x-win-bitmap" "image/vnd.microsoft.icon" 
"application/ico" "image/ico" "image/icon" "text/ico" ""
-"ico" "cur" ""
-"  \001   " "zz znz" 100
-"  \002   " "zz znz" 100
-
-"/gnu/store/m4ccn9nzlsbvlj36w45555pq98spy007-gdk-pixbuf-2.34.0/lib/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-pnm.so"
-"pnm" 4 "gdk-pixbuf" "PNM/PBM/PGM/PPM" "LGPL"
-"image/x-portable-anymap" "image/x-portable-bitmap" "image/x-portable-graymap" 
"image/x-portable-pixmap" ""
-"pnm" "pbm" "pgm" "ppm" ""
-"P1" "" 100
-"P2" "" 100
-"P3" "" 100
-"P4" "" 100
-"P5" "" 100
-"P6" "" 100
-
--8<---------------cut here---------------end--------------->8---

Presumably ‘gdk-pixbuf-query-loaders’, which generates ‘loaders.cache’,
does not sort the entries returned by readdir(2).

Ludo’.