dyld error when enabling tests for tk +quartz

[chrstphrchvz (Christopher Chavez)]

Using Tk 8.6.8/8.6.9rc4 on macOS 10.14.1.

If I manually add test.run yes to the tk portfile under the +quartz variant, and run port -vt test tk +quartz, there is an error:

DYLD_LIBRARY_PATH="`pwd`:/opt/local/lib:${DYLD_LIBRARY_PATH}"; export DYLD_LIBRARY_PATH; … 
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

(​full test log)

I'm guessing /opt/local/lib/libJPEG.dylib should instead be /opt/local/lib/libjpeg.dylib (note this is on a case-insensitive APFS volume).

There have been ​tickets for similar errors on other ports, and one common diagnosis is that ports shouldn't use/set DYLD_LIBRARY_PATH.

I'm inclined to think this is a MacPorts-specific issue but haven't ruled out it being an upstream issue.

I am unsure whether tests should be runnable for +quartz. My impression is they were left out of the portfile mainly because they can't be run for the +x11 variant (since port runs tests as the macports user, which can't access the X11 server).

[MarcusCalhoun-Lopez (Marcus Calhoun-Lopez)]

This is a know issue.
DYLD_FALLBACK_LIBRARY_PATH should be used instead of DYLD_LIBRARY_PATH.

If we run otool -L /System/Library/Frameworks/ImageIO.framework/Versions/A/ImageIO, we see that the library uses /System/Library/Frameworks/ImageIO.framework/Versions/A/Resources/libJPEG.dylib.
When DYLD_FALLBACK_LIBRARY_PATH is set to ${prefix}/lib, we force ImageIO to use ${prefix}/lib/libjpeg.dylib instead.
Th two libjpeg.dylibs have different symbols, hence the error.

DYLD_FALLBACK_LIBRARY_PATH goes looking for other libraries only if the requested one cannot be found.

This issue has cropped up from time to time.
​tix and ​cargo are two I can think of off the top of my head.

[MarcusCalhoun-Lopez (Marcus Calhoun-Lopez)]

In 97d4a4bb23681f5bc2c8abb15c77d2e50c9e1de0/macports-ports (master):

tk: enable tests

Fixes #57594

[kencu (Ken)]

There is a minor typo in that comment. You said:

When DYLD_FALLBACK_LIBRARY_PATH is set to ${prefix}/lib, we force ImageIO to use ${prefix}/lib/libjpeg.dylib instead.

but I think you meant:

When DYLD_LIBRARY_PATH is set to ${prefix}/lib, we force ImageIO to use ${prefix}/lib/libjpeg.dylib instead.

[kencu (Ken)]

BTW - would this only show up on case-insensitive file systems? libjpeg vs libJPEG? Maybe that's why some people don't seem to see it.

[MarcusCalhoun-Lopez (Marcus Calhoun-Lopez)]

Thank you for pointing this out.
I have made the edit.

Replying to kencu:

There is a minor typo in that comment. You said:

When DYLD_FALLBACK_LIBRARY_PATH is set to ${prefix}/lib, we force ImageIO to use ${prefix}/lib/libjpeg.dylib instead.

but I think you meant:

When DYLD_LIBRARY_PATH is set to ${prefix}/lib, we force ImageIO to use ${prefix}/lib/libjpeg.dylib instead.