Trouble with emcc 6.0.0 from #25930

I'm not 100% sure what the problem is but emcc 6.0.0 works fine for me if I revert #25930. The problem is that -Bstatic is passed when I'm trying to link a static library.

I think the problem is that the condition here is wrong:

  if settings.FAKE_DYLIBS or (not settings.MAIN_MODULE and not settings.SIDE_MODULE):
    cmd.append('-Bstatic')
  else:
    # wasm-ld still defaults to static linking by default. If that ever changes, we can remove this line.
    cmd.append('-Bdynamic')

emscripten/tools/building.py

Lines 167 to 172 in 6d8b2c1

    
           if settings.FAKE_DYLIBS or (not settings.MAIN_MODULE and not settings.SIDE_MODULE): 
        
             cmd.append('-Bstatic') 
        
           else: 
        
             # wasm-ld still defaults to static linking by default. If that ever changes, we can remove this line. 
        
             cmd.append('-Bdynamic')

Maybe it should be:

if settings.FAKE_DYLIBS and (not settings.MAIN_MODULE and not settings.SIDE_MODULE):

Well this patch:

   if settings.FAKE_DYLIBS or (not settings.MAIN_MODULE and not settings.SIDE_MODULE):
-    cmd.append('-Bstatic')
+    pass

fixes the build but it still breaks at runtime.

Do you know why passing -Bstatic would be a problem when linking a static library? Are you passing either -Bstatic or -Bdynamic yourself, or are we just talking about the internal injection of these flags?

It's trying to link a shared library into a static library and failing. Either they should both be dynamic or both be static and I'm not sure which. Perhaps it involves some strange combination of flags which work on more standard linkers.

Do you want what the intent of the build is? Maybe you should share the full build command that is being used to build this library (either the emcc or the host version).

I'm a little confused what you mean by "trying to link a shared library into a static library and failing" since static libraries are not linked at all using emcc right? They use emar

Apparently I misunderstood the issue, binary searching the diff shows that the problem is that it was passing --whole-archive before and now it's not. It's this one line that causes the problem:
https://github.com/emscripten-core/emscripten/pull/25930/changes#diff-e6615de4338b98e08471c53f2d6fc250dc6ca22cd8c303ac33ab259c18ae68d2R288

Reverting that one change makes it work as before:

-  if settings.LINKABLE and (settings.FAKE_DYLIBS or not settings.SIDE_MODULE):
+  if settings.LINKABLE:
     args.insert(0, '--whole-archive')
     args.append('--no-whole-archive')

I think it maybe should read:

if settings.LINKABLE and (settings.FAKE_DYLIBS or settings.SIDE_MODULE != 2):

because I think SIDE_MODULE=1 is supposed to imply --whole-archive but it seems like it doesn't anymore?

Okay opened a PR with that.

[dylink] Restore `--whole-archive` when linking with `-sSIDE_MODULE=1`

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Trouble with emcc 6.0.0 from #25930 #27403

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	if settings.FAKE_DYLIBS or (not settings.MAIN_MODULE and not settings.SIDE_MODULE):
	cmd.append('-Bstatic')
	else:
	# wasm-ld still defaults to static linking by default. If that ever changes, we can remove this line.
	cmd.append('-Bdynamic')

Trouble with emcc 6.0.0 from #25930 #27403

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hoodmane commented on Jul 22, 2026

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hoodmane commented on Jul 28, 2026

hoodmane commented on Jul 28, 2026

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