This patch changes Guile to use a default search path relative to the
location of the `guile' binary, allowing it to be relocated.

--- a/libguile/load.c
+++ b/libguile/load.c
@@ -26,6 +26,7 @@
 
 #include <string.h>
 #include <stdio.h>
+#include <libgen.h>
 
 #include "libguile/_scm.h"
 #include "libguile/alist.h"
@@ -326,6 +327,32 @@ scm_init_load_path ()
   SCM cpath = SCM_EOL;
 
 #ifdef SCM_LIBRARY_DIR
+  char *program, *bin_dir, *prefix, *module_dir, *ccache_dir;
+
+  /* Determine the source and compiled module directories at run-time,
+     relative to the executable's location.
+
+     Note: Use /proc/self/exe instead of argv[0] because the latter is
+     not necessarily an absolute, nor a valid file name.  */
+
+  program = scm_gc_malloc_pointerless (256, "string");
+  readlink ("/proc/self/exe", program, 256);
+
+  bin_dir = dirname (strdupa (program));
+
+  prefix = scm_gc_malloc_pointerless (strlen (bin_dir) + 4, "string");
+  strcpy (prefix, bin_dir);
+  strcat (prefix, "/..");
+  prefix = canonicalize_file_name (prefix);
+
+  module_dir = scm_gc_malloc_pointerless (strlen (prefix) + 50, "string");
+  strcpy (module_dir, prefix);
+  strcat (module_dir, "/share/guile/" SCM_EFFECTIVE_VERSION);
+
+  ccache_dir = scm_gc_malloc_pointerless (strlen (prefix) + 50, "string");
+  strcpy (ccache_dir, prefix);
+  strcat (ccache_dir, "/lib/guile/" SCM_EFFECTIVE_VERSION "/ccache");
+
   env = scm_i_mirror_backslashes (getenv ("GUILE_SYSTEM_PATH"));
   if (env && strcmp (env, "") == 0)
     /* special-case interpret system-path=="" as meaning no system path instead
@@ -334,10 +361,7 @@ scm_init_load_path ()
   else if (env)
     path = scm_parse_path (scm_from_locale_string (env), path);
   else
-    path = scm_list_4 (scm_from_utf8_string (SCM_LIBRARY_DIR),
-                       scm_from_utf8_string (SCM_SITE_DIR),
-                       scm_from_utf8_string (SCM_GLOBAL_SITE_DIR),
-                       scm_from_utf8_string (SCM_PKGDATA_DIR));
+    path = scm_list_1 (scm_from_locale_string (module_dir));
 
   env = scm_i_mirror_backslashes (getenv ("GUILE_SYSTEM_COMPILED_PATH"));
   if (env && strcmp (env, "") == 0)
@@ -347,8 +371,7 @@ scm_init_load_path ()
     cpath = scm_parse_path (scm_from_locale_string (env), cpath);
   else
     {
-      cpath = scm_list_2 (scm_from_utf8_string (SCM_CCACHE_DIR),
-                          scm_from_utf8_string (SCM_SITE_CCACHE_DIR));
+      cpath = scm_list_1 (scm_from_locale_string (ccache_dir));
     }
 
 #endif /* SCM_LIBRARY_DIR */
og/gnu/packages/fpga.scm?id=9969b436af8c2892e59ed14ffe94905b6b18c005&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2019-06-08 07:30:26 +0200'>2019-06-08</span></td><td><a href='/guix/commit/gnu/packages/fpga.scm?id=7e6764c1d290a4233a34b5e6751c6d89f05823a6'>gnu: gtkwave: Update to 3.3.101.</a><span class='msg-avail'>...</span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2019-04-17 06:15:36 +0200'>2019-04-17</span></td><td><a href='/guix/commit/gnu/packages/fpga.scm?id=38dd8b60585fea6749a4fcd35ce167bdee8fb2e6'>gnu: gtkwave: Update to 3.3.100.</a><span class='msg-avail'>...</span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2019-04-17 06:12:48 +0200'>2019-04-17</span></td><td><a href='/guix/commit/gnu/packages/fpga.scm?id=315d7dda35b62b9b6c93cc9e655fb35125fcf45c'>gnu: gtkwave: Don't use NAME in source URI.</a><span class='msg-avail'>...</span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2019-03-12 02:22:35 +0100'>2019-03-12</span></td><td><a href='/guix/commit/gnu/packages/fpga.scm?id=3d21f1ea0f68a8741f168ea32368c68b57269f5b'>gnu: gtkwave: Update to 3.3.99.</a><span class='msg-avail'>...</span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2019-01-15 16:46:45 +0100'>2019-01-15</span></td><td><a href='/guix/commit/gnu/packages/fpga.scm?id=9210a6c082cb201b46aa50eea9aecc4334ead83a'>gnu: yosys: Update to 0.8.</a><span class='msg-avail'>...</span></td><td>Danny Milosavljevic</td></tr>
<tr><td><span title='2019-01-15 16:46:45 +0100'>2019-01-15</span></td><td><a href='/guix/commit/gnu/packages/fpga.scm?id=eccd3f6d2ef09fcfccf5e4e09be13b79089c60d1'>gnu: arachne-pnr: Fix tests.</a><span class='msg-avail'>...</span></td><td>Danny Milosavljevic</td></tr>
<tr><td><span title='2019-01-15 16:46:45 +0100'>2019-01-15</span></td><td><a href='/guix/commit/gnu/packages/fpga.scm?id=72dd271cee8d38349b43d8a1a4fd5b6942952a42'>gnu: icestorm: Update to 0.0-2-c0cbae88a.</a><span class='msg-avail'>...</span></td><td>Danny Milosavljevic</td></tr>
<tr><td><span title='2019-01-15 16:46:43 +0100'>2019-01-15</span></td><td><a href='/guix/commit/gnu/packages/fpga.scm?id=e82baf69f18f42b58e8929000ca4b665a74d86b4'>gnu: arachne-pnr: Update to 840bdfdeb.</a><span class='msg-avail'>...</span></td><td>Amin Bandali</td></tr>