depot/third_party/nixpkgs/pkgs/development/tools/misc/gdb/debug-info-from-env.patch

--- a/gdb/main.c
+++ b/gdb/main.c
@@ -708,8 +708,12 @@ captured_main_1 (struct captured_main_args *context)
   if (gdb_sysroot.empty ())
     gdb_sysroot = TARGET_SYSROOT_PREFIX;
 
-  debug_file_directory
-    = relocate_gdb_directory (DEBUGDIR, DEBUGDIR_RELOCATABLE);
+  const char * nix_debug = getenv ("NIX_DEBUG_INFO_DIRS");
+  if (nix_debug != NULL)
+      debug_file_directory = nix_debug;
+  else
+    debug_file_directory
+      = relocate_gdb_directory (DEBUGDIR, DEBUGDIR_RELOCATABLE);
 
   gdb_datadir = relocate_gdb_directory (GDB_DATADIR,
 					GDB_DATADIR_RELOCATABLE);