Bug #14992: mkmf sets DYLD_LIBRARY_PATH on macOS which breaks pkg-config

• Status: Closed
• Assignee: -
• Target version: -
• ruby -v: ruby 2.5.1p57 (2018-03-29 revision 63029) [x86_64-darwin17]
• Backport: 2.3: UNKNOWN, 2.4: UNKNOWN, 2.5: REQUIRED

[stevecheckoway (Stephen Checkoway)]

When mkmf runs pkg-config, it sets DYLD_LIBRARY_PATH on macOS which causes pkg-config to not work. As an example, running

$ ruby2.5 -r mkmf -e 'pkg_config("libxml-2.0")'

writes the following to mkmf.log.

"pkg-config --exists libxml-2.0"
dyld: Symbol not found: __cg_jpeg_resync_to_restart
  Referenced from: /System/Library/Frameworks/ImageIO.framework/Versions/A/ImageIO
  Expected in: /opt/local/lib/libJPEG.dylib
 in /System/Library/Frameworks/ImageIO.framework/Versions/A/ImageIO
package configuration for libxml-2.0 is not found

The same behavior results from running pkg-config with DYLD_LIBRARY_PATH set.

$ DYLD_LIBRARY_PATH=.:/opt/local/lib pkg-config --exists libxml-2.0
dyld: Symbol not found: __cg_jpeg_resync_to_restart
  Referenced from: /System/Library/Frameworks/ImageIO.framework/Versions/A/ImageIO
  Expected in: /opt/local/lib/libJPEG.dylib
 in /System/Library/Frameworks/ImageIO.framework/Versions/A/ImageIO
Abort trap: 6

I verified that mkmf is responsible for setting this by writing the following pkg-config.c file, compiling it as pkg-config, and then running the ruby2.5 command above with . at the front of my PATH.

pkg-config.c:

#include <stdio.h>
#include <stdlib.h>

int main() {
	printf("DYLD_LIBRARY_PATH=%s\n", getenv("DYLD_LIBRARY_PATH"));
	return 1;
}

$ ./pkg-config
DYLD_LIBRARY_PATH=(null)
$ PATH=.:$PATH ruby2.5 -r mkmf -e 'pkg_config("libxml-2.0")'
$ cat mkmf.log
"pkg-config --exists libxml-2.0"
DYLD_LIBRARY_PATH=.:/opt/local/lib
package configuration for libxml-2.0 is not found

I don't know why DYLD_LIBRARY_PATH is being set, but I don't believe it should be. It's not respected by system binaries on macOS and macOS has supported methods of embedding run-time paths in binaries, executables, and bundles that probably should be used instead.

[nobu (Nobuyoshi Nakada)]

• Status changed from Open to Closed

Applied in changeset trunk|r64392.

---

configure.ac: LIBPATHENV on macOS

• configure.ac (LIBPATHENV): use DYLD_FALLBACK_LIBRARY_PATH instead of
  DYLD_LIBRARY_PATH on macOS, to honor runtime paths embedded in the
  binaries. [ruby-core:88487] [Bug #14992]

[nagachika (Tomoyuki Chikanaga)]

• Backport changed from 2.3: UNKNOWN, 2.4: UNKNOWN, 2.5: UNKNOWN to 2.3: UNKNOWN, 2.4: UNKNOWN, 2.5: REQUIRED