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 */
2</span></td><td><a href='/guix/commit/doc/images?id=cd5d5f53228fd5bf96d9f790aa2606ae71fa68d7'>doc: Update 'Bootstrapping' for further binary seed reduction.</a><span class='msg-avail'>...</span></td><td>Jan Nieuwenhuizen</td></tr>
<tr><td><span title='2019-03-14 16:30:19 +0100'>2019-03-14</span></td><td><a href='/guix/commit/doc/images?id=19008a22d18e772062952034c58a15ed341df3b5'>Merge branch 'staging' into core-updates</a></td><td>Marius Bakke</td></tr>
<tr><td><span title='2019-03-13 23:12:43 +0100'>2019-03-13</span></td><td><a href='/guix/commit/doc/images?id=e1c15e8b8e25e14c253ff1212e289565736f6ea7'>doc: Document the graphical installer some more.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2018-12-16 22:49:10 +0100'>2018-12-16</span></td><td><a href='/guix/commit/doc/images?id=b3bf38a5600d0fdcb0aeed29ee121edef632165d'>doc: Update mesboot graph without bootstrap-guile.</a><span class='msg-avail'>...</span></td><td>Jan Nieuwenhuizen</td></tr>
<tr><td><span title='2018-11-24 08:18:31 +0100'>2018-11-24</span></td><td><a href='/guix/commit/doc/images?id=3d3daf7fa1794c64914ed53e51838a41d9b7adc4'>doc: Update for bootstrap-mescc-tools change.</a><span class='msg-avail'>...</span></td><td>Jan Nieuwenhuizen</td></tr>