nixpkgs/pkgs/applications/video/avidemux/dynamic_install_dir.patch

diff -ru3 avidemux_2.6.12.old/avidemux_core/ADM_core/src/ADM_fileio.cpp avidemux_2.6.12/avidemux_core/ADM_core/src/ADM_fileio.cpp
--- avidemux_2.6.12.old/avidemux_core/ADM_core/src/ADM_fileio.cpp	2016-03-25 15:26:00.368213627 +0300
+++ avidemux_2.6.12/avidemux_core/ADM_core/src/ADM_fileio.cpp	2016-03-26 02:32:56.163550537 +0300
@@ -393,7 +393,7 @@
 
 	return ADM_getRelativePath(buffer, base1, base2, base3);
 #else
-	return ADM_getRelativePath(ADM_INSTALL_DIR, base1, base2, base3);
+	return ADM_getRelativePath(getenv("ADM_ROOT_DIR"), base1, base2, base3);
 #endif
 }