nixpkgs/pkgs/development/libraries/libbacktrace/0004-libbacktrace-Support-NIX_DEBUG_INFO_DIRS-environment.patch

From 884ef7c843be906d62e4240c2a0e885dcd5a5726 Mon Sep 17 00:00:00 2001
From: Jan Tojnar <jtojnar@gmail.com>
Date: Sat, 24 Dec 2022 20:30:22 +0100
Subject: [PATCH 4/4] libbacktrace: Support NIX_DEBUG_INFO_DIRS environment
 variable
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Let’s make debug data lookup work on NixOS just like in gdb.
---
 elf.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/elf.c b/elf.c
index ccffa95..e86950d 100644
--- a/elf.c
+++ b/elf.c
@@ -6946,11 +6946,18 @@ elf_add (struct backtrace_state *state, const char *filename, int descriptor,
 
   if (buildid_data != NULL)
     {
+      const char *debug_directories_immutable;
+      const char *nix_debug = getenv ("NIX_DEBUG_INFO_DIRS");
+      if (nix_debug != NULL)
+        debug_directories_immutable = nix_debug;
+      else
+        debug_directories_immutable = SYSTEM_DEBUG_DIR;
+
       int d;
-      char debug_directories[strlen(SYSTEM_DEBUG_DIR) + 1];
+      char debug_directories[strlen(debug_directories_immutable) + 1];
       char *debug_dir;
 
-      strcpy(debug_directories, SYSTEM_DEBUG_DIR);
+      strcpy(debug_directories, debug_directories_immutable);
 
       debug_dir = strtok (debug_directories, ":");
       while (debug_dir != NULL)
-- 
2.43.1