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

diff --git a/libguile/load.c b/libguile/load.c
--- a/libguile/load.c
+++ b/libguile/load.c
@@ -27,6 +27,7 @@
 #include <stat-time.h>
 #include <string.h>
 #include <stdio.h>
+#include <libgen.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <unistd.h>
@@ -334,6 +335,32 @@ 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
@@ -342,10 +369,7 @@ 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)
@@ -355,8 +379,7 @@ 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 */
s='msg-tooltip'>That choice was made in 2014 and never made much sense.

* guix.scm (%public-modules): Remove 'ftp-client'.
</span></span></td><td>Ludovic Courtès</td></tr>