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"
@@ -325,6 +326,32 @@
   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
@@ -333,10 +360,7 @@
   else if (env)
     path = scm_parse_path (scm_from_locale_string (env), path);
   else
-    path = scm_list_4 (scm_from_locale_string (SCM_LIBRARY_DIR),
-                       scm_from_locale_string (SCM_SITE_DIR),
-                       scm_from_locale_string (SCM_GLOBAL_SITE_DIR),
-                       scm_from_locale_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)
@@ -346,8 +370,7 @@
     cpath = scm_parse_path (scm_from_locale_string (env), cpath);
   else
     {
-      cpath = scm_list_2 (scm_from_locale_string (SCM_CCACHE_DIR),
-                          scm_from_locale_string (SCM_SITE_CCACHE_DIR));
+      cpath = scm_list_1 (scm_from_locale_string (ccache_dir));
     }
 
 #endif /* SCM_LIBRARY_DIR */
><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/tests/containers.scm?id=6e8cdf1d26092cb9654e179b04730fff7c15c94f'>Collapse</a>)</th><th class='left'>Author</th></tr>
<tr class='logheader'><td><span title='2020-10-01 12:51:13 +0200'>2020-10-01</span></td><td class='logsubject'><a href='/guix/commit/tests/containers.scm?id=e74818353882f187e5971b5a3a481f17df883dbe'>linux-container: Reset jailed root permissions.</a></td><td>Jelle Licht</td></tr>
<tr class='nohover-highlight'><td/><td colspan='3' class='logmsg'>
* gnu/build/linux-container.scm (mount-file-systems): Add 'chmod' call.
* tests/containers.scm
("call-with-container, mnt namespace, root permissions"): New test.


</td></tr>
<tr class='logheader'><td><span title='2019-10-15 10:21:41 +0200'>2019-10-15</span></td><td class='logsubject'><a href='/guix/commit/tests/containers.scm?id=e464ac667297d2acf57e52438a39cadc87b95da2'>tests: Skip container test when lacking kernel support.</a></td><td>Ludovic Courtès</td></tr>
<tr class='nohover-highlight'><td/><td colspan='3' class='logmsg'>
This is a followup to 96b35998e610c7fc37bf87bf9e07e63d3bebd0a3.

* tests/containers.scm ("eval/container, non-empty load path"): Add
missing 'skip-if-unsupported' call.


</td></tr>
<tr class='logheader'><td><span title='2019-09-18 23:08:28 +0200'>2019-09-18</span></td><td class='logsubject'><a href='/guix/commit/tests/containers.scm?id=96b35998e610c7fc37bf87bf9e07e63d3bebd0a3'>linux-container: 'eval/container' correctly passes -L and -C flags.</a></td><td>Ludovic Courtès</td></tr>
<tr class='nohover-highlight'><td/><td colspan='3' class='logmsg'>
This fixes a type error.

* gnu/system/linux-container.scm (eval/container): Use 'append-map', not
'map'.
* tests/containers.scm ("eval/container, non-empty load path"): New test.


</td></tr>
<tr class='logheader'><td><span title='2019-07-19 11:53:47 +0200'>2019-07-19</span></td><td class='logsubject'><a href='/guix/commit/tests/containers.scm?id=bacfec8611530dc3e849fb804b51f50b299796f0'>linux-container: Add 'eval/container'.</a></td><td>Ludovic Courtès</td></tr>
<tr class='nohover-highlight'><td/><td colspan='3' class='logmsg'>
* gnu/system/linux-container.scm (eval/container): New procedure.
* tests/containers.scm ("eval/container, exit status")
("eval/container, writable user mapping"): New tests.


</td></tr>
<tr class='logheader'><td><span title='2019-04-02 18:15:37 +0200'>2019-04-02</span></td><td class='logsubject'><a href='/guix/commit/tests/containers.scm?id=af76c020bf19de5fe2e92f31d8b85cbd55c481de'>linux-container: Make the guest UID and GID a parameter.</a></td><td>Ludovic Courtès</td></tr>
<tr class='nohover-highlight'><td/><td colspan='3' class='logmsg'>
* gnu/build/linux-container.scm (initialize-user-namespace): Add
 #:guest-uid and #:guest-gid parameters and honor them.
(run-container): Likewise.
(call-with-container): Likewise.
* tests/containers.scm ("call-with-container, user namespace, guest UID/GID"):
New test.


</td></tr>