WASM backend doesn't work

[hasufell]

Reproduce:

1. git clone https://github.com/stable-haskell/ghc.git && git submodule update --init
2. git checkout stable-ghc-9.14
3. apply this patch: https://gist.github.com/hasufell/93cb545d57ba1ea00f0fec151c08c5a1
4. make CABAL=_build/stage0/bin/cabal stage2
5. install wasm-meta as described here: https://www.haskell.org/ghcup/guide/#ghc-wasm-cross-bindists-experimental but don't perform the last step: source ~/.ghc-wasm/env!
6. edit ~/.ghc-wasm/env to only include the PATH changes and source it
7. make CABAL=_build/stage0/bin/cabal stage3-wasm32-unknown-wasi

Result should be something like:

Building library 'nonthreaded-nodebug' for rts-1.0.3...
wasm-ld: error: symbol type mismatch: stg_ap_pv_info
>>> defined as WASM_SYMBOL_TYPE_DATA in /home/hasufell/git/ghc/_build/stage3/wasm32-unknown-wasi/build/host/wasm32-wasi/ghc-9.14/rts-1.0.3-nonthreaded-nodebug/build/nonthreaded-nodebug/RaiseAsync.dyn_o
>>> defined as WASM_SYMBOL_TYPE_FUNCTION in /home/hasufell/git/ghc/_build/stage3/wasm32-unknown-wasi/build/host/wasm32-wasi/ghc-9.14/rts-1.0.3-nonthreaded-nodebug/build/nonthreaded-nodebug/Exception.dyn_o

wasm-ld: error: symbol type mismatch: stg_BLACKHOLE_info
>>> defined as WASM_SYMBOL_TYPE_DATA in /home/hasufell/git/ghc/_build/stage3/wasm32-unknown-wasi/build/host/wasm32-wasi/ghc-9.14/rts-1.0.3-nonthreaded-nodebug/build/nonthreaded-nodebug/Messages.dyn_o
>>> defined as WASM_SYMBOL_TYPE_FUNCTION in /home/hasufell/git/ghc/_build/stage3/wasm32-unknown-wasi/build/host/wasm32-wasi/ghc-9.14/rts-1.0.3-nonthreaded-nodebug/build/nonthreaded-nodebug/StgMiscClosures.dyn_o

wasm-ld: error: symbol type mismatch: stg_marked_upd_frame_info
>>> defined as WASM_SYMBOL_TYPE_DATA in /home/hasufell/git/ghc/_build/stage3/wasm32-unknown-wasi/build/host/wasm32-wasi/ghc-9.14/rts-1.0.3-nonthreaded-nodebug/build/nonthreaded-nodebug/ThreadPaused.dyn_o
>>> defined as WASM_SYMBOL_TYPE_FUNCTION in /home/hasufell/git/ghc/_build/stage3/wasm32-unknown-wasi/build/host/wasm32-wasi/ghc-9.14/rts-1.0.3-nonthreaded-nodebug/build/nonthreaded-nodebug/Updates.dyn_o
wasm32-wasi-clang: error: linker command failed with exit code 1 (use -v to see invocation)
`wasm32-wasi-clang' failed in phase `Linker'. (Exit code: 1)

Motivation: test the https://gitlab.haskell.org/ghc/ghc/-/commit/867c26755e8855c6df949e65df0c2aebc9da64c3 change and whether that resolves the recursive loading issues.

[hsyl20]

Step 4 fails with:

❯ make CABAL=_build/stage0/bin/cabal stage2
Error: [Cabal-7130]
Internal error in target matching: could not make an unambiguous fully qualified target selector for 'cabal-install:exe:cabal'.
We made the target 'cabal-install:exe:cabal' (unknown-component) that was expected to be unambiguous but matches the following targets:
'cabal-install:exe:cabal', matching:
  - cabal-install:exe:cabal (unknown-component)
  - cabal-install:exe:cabal (unknown-file)
':pkg:cabal-install:exe:cabal', matching:
  - cabal-install:exe:cabal (unknown-component)

Note: Cabal expects to be able to make a single fully qualified name for a target or provide a more specific error. Our failure to do so is a bug in cabal. Tracking issue: https://github.com/haskell/cabal/issues/8684

Hint: this may be caused by trying to build a package that exists in the project directory but is missing from the 'packages' stanza in your cabal project file.

::group::Building Cabal...
cabal build -j -w ghc-9.8.4 --disable-tests --project-dir libraries/Cabal --builddir=/home/hsyl20/projects/ghc/scratch/stable-wasm/ghc/_build/stage0 --ghc-options="-fhide-source-paths" cabal-install:exe:cabal
Error: [Cabal-7130]
Internal error in target matching: could not make an unambiguous fully qualified target selector for 'cabal-install:exe:cabal'.
We made the target 'cabal-install:exe:cabal' (unknown-component) that was expected to be unambiguous but matches the following targets:
'cabal-install:exe:cabal', matching:
  - cabal-install:exe:cabal (unknown-component)
  - cabal-install:exe:cabal (unknown-file)
':pkg:cabal-install:exe:cabal', matching:
  - cabal-install:exe:cabal (unknown-component)

Note: Cabal expects to be able to make a single fully qualified name for a target or provide a more specific error. Our failure to do so is a bug in cabal. Tracking issue: https://github.com/haskell/cabal/issues/8684

Hint: this may be caused by trying to build a package that exists in the project directory but is missing from the 'packages' stanza in your cabal project file.

make: *** [Makefile:601: _build/stage0/bin/cabal] Error 1

[hasufell]

did you check out all the submodules?

[hsyl20]

No I forgot. I've blindly followed the steps ^^

[hsyl20]

It fails in step 7 with:

❯ make CABAL=_build/stage0/bin/cabal stage3-wasm32-unknown-wasi
echo "" > cabal.project.stage1.local
_build/stage0/bin/cabal --remote-repo-cache _build/packages --store-dir=_build/stage1/x86_64-unknown-linux/store --logs-dir=_build/stage1/logs update
Warning: this is a debug build of cabal-install with assertions enabled.
Downloading the latest package list from hackage.haskell.org
Package list of hackage.haskell.org has been updated.
The index-state is set to 2026-01-13T08:53:37Z.
To revert to previous state run:
    cabal v2-update 'hackage.haskell.org,2026-01-13T08:52:55Z'
::group::Building stage1 executables (deriveConstants genapply genprimopcode ghc ghc-pkg ghc-toolchain-bin hsc2hs unlit)...
# Force cabal to replan
rm -rf _build/stage1/cache
HADRIAN_SETTINGS='[ ("hostPlatformArch",    "ArchX86_64") , ("hostPlatformOS",      "OSLinux") , ("cProjectGitCommitId", "9cbe6d34edafdea267f889257791f572ed4fbe7e") , ("cProjectVersion",     "9.14") , ("cProjectVersionInt",  "914") , ("cProjectPatchLevel",  "0") , ("cProjectPatchLevel1", "0") , ("cProjectPatchLevel2", "0") ]' _build/stage0/bin/cabal --remote-repo-cache _build/packages --store-dir=_build/stage1//store --logs-dir=_build/stage1/logs build -j -w ghc-9.8.4 --with-gcc=/home/hsyl20/.ghc-wasm/wasi-sdk/bin/wasm32-wasi-clang --with-ld=/home/hsyl20/.ghc-wasm/wasi-sdk/bin/wasm-ld --project-file=cabal.project.stage1   --builddir=_build/stage1/ --ghc-options="-fhide-source-paths" deriveConstants:deriveConstants genapply:genapply genprimopcode:genprimopcode ghc-pkg:ghc-pkg hsc2hs:hsc2hs rts-headers:rts-headers unlit:unlit ghc-bin:ghc ghc-toolchain-bin:ghc-toolchain-bin
Warning: this is a debug build of cabal-install with assertions enabled.
Toolchains:
- build compiler ghc-9.8.4
- host compiler ghc-9.8.4
Resolving dependencies...
Build profile: -w ghc-9.8.4 -W ghc-9.8.4 -O1
In order, the following will be built (use -v for more details):
 - build unix-2.8.8.0 (lib) (configuration changed)
 - host genapply-0.1 (exe:genapply) (configuration changed)
 - host ghc-boot-th-next-9.14 (lib) (configuration changed)
 - host ghc-platform-0.1.0.0 (lib) (configuration changed)
 - host libffi-clib-3.5.2 (lib) (configuration changed)
 - host os-string-2.0.8 (lib) (configuration changed)
 - host rts-fs-1.0.0.0 (lib) (configuration changed)
 - host rts-headers-1.0.3 (lib) (configuration changed)
 - build file-io-0.1.5 (lib) (configuration changed)
 - host filepath-1.5.4.0 (lib) (configuration changed)
 - host unlit-0.1 (exe:unlit) (configuration changed)
 - build directory-1.3.10.0 (lib) (configuration changed)
 - host unix-2.8.8.0 (lib) (configuration changed)
 - build process-1.6.26.1 (lib) (configuration changed)
 - build alex-3.5.4.0 (exe:alex) (configuration changed)
 - host semaphore-compat-1.0.0 (lib) (configuration changed)
 - host file-io-0.1.5 (lib) (configuration changed)
 - build deriveConstants-0.1 (exe:deriveConstants) (configuration changed)
 - host genprimopcode-0.1 (exe:genprimopcode) (configuration changed)
 - build genprimopcode-0.1 (exe:genprimopcode) (configuration changed)
 - build Cabal-syntax-3.17.0.0 (lib) (configuration changed)
 - host directory-1.3.10.0 (lib) (configuration changed)
 - build Cabal-3.17.0.0 (lib) (configuration changed)
 - host process-1.6.26.1 (lib) (configuration changed)
 - host hpc-0.7.0.2 (lib) (configuration changed)
 - host Cabal-syntax-3.17.0.0 (lib) (configuration changed)
 - host ghc-boot-9.14 (lib:ghc-boot) (configuration changed)
 - host hsc2hs-0.68.10 (exe:hsc2hs) (configuration changed)
 - host ghc-toolchain-0.1.0.0 (lib) (configuration changed)
 - host deriveConstants-0.1 (exe:deriveConstants) (configuration changed)
 - host Cabal-3.17.0.0 (lib) (configuration changed)
 - host ghci-9.14 (lib) (configuration changed)
 - host ghc-toolchain-bin-0.1.0.0 (exe:ghc-toolchain-bin) (configuration changed)
 - host ghc-pkg-9.14 (exe:ghc-pkg) (configuration changed)
 - host ghc-9.14 (lib:ghc) (configuration changed)
 - host ghc-bin-9.14 (exe:ghc) (configuration changed)
Warning: this is a debug build of cabal-install with assertions enabled.
Configuring library for unix-2.8.8.0...
Warning: this is a debug build of cabal-install with assertions enabled.
Configuring executable 'genapply' for genapply-0.1...
Warning: this is a debug build of cabal-install with assertions enabled.
Configuring library for ghc-boot-th-next-9.14...
Warning: this is a debug build of cabal-install with assertions enabled.
Configuring library for ghc-platform-0.1.0.0...
Warning: this is a debug build of cabal-install with assertions enabled.
Configuring library for libffi-clib-3.5.2...
Warning: this is a debug build of cabal-install with assertions enabled.
Configuring library for os-string-2.0.8...
Warning: this is a debug build of cabal-install with assertions enabled.
Configuring library for rts-fs-1.0.0.0...
Warning: this is a debug build of cabal-install with assertions enabled.
Configuring library for rts-headers-1.0.3...
wasm32-wasi-clang: warning: argument unused during compilation: '-fuse-ld=lld' [-Wunused-command-line-argument]
wasm32-wasi-clang: warning: argument unused during compilation: '-fuse-ld=lld' [-Wunused-command-line-argument]
wasm32-wasi-clang: warning: argument unused during compilation: '-fuse-ld=lld' [-Wunused-command-line-argument]
wasm32-wasi-clang: warning: argument unused during compilation: '-fuse-ld=lld' [-Wunused-command-line-argument]
Warning: [relative-path-outside] 'hs-source-dirs: ../ghc-boot-th' is a relative path outside of the source tree. This will not work when generating a tarball with 'sdist'.
Warning: [relative-path-outside] 'hs-source-dirs: ../ghc-internal/src' is a relative path outside of the source tree. This will not work when generating a tarball with 'sdist'.
Warning: [unknown-file] The 'license-file' field refers to the file 'LICENSE' which does not exist.
configure: WARNING: unrecognized options: --with-compiler
wasm32-wasi-clang: warning: argument unused during compilation: '-fuse-ld=lld' [-Wunused-command-line-argument]
wasm32-wasi-clang: warning: argument unused during compilation: '-fuse-ld=lld' [-Wunused-command-line-argument]
checking for gcc... /home/hsyl20/.ghc-wasm/wasi-sdk/bin/wasm32-wasi-clang
wasm32-wasi-clang: warning: argument unused during compilation: '-fuse-ld=lld' [-Wunused-command-line-argument]
wasm32-wasi-clang: warning: argument unused during compilation: '-fuse-ld=lld' [-Wunused-command-line-argument]
Warning: this is a debug build of cabal-install with assertions enabled.
checking whether the C compiler works... Warning: this is a debug build of cabal-install with assertions enabled.
Preprocessing executable 'genapply' for genapply-0.1...
Building executable 'genapply' for genapply-0.1...
configure: WARNING: unrecognized options: --with-compiler
Warning: this is a debug build of cabal-install with assertions enabled.
yes
checking for C compiler default output file name... a.out
checking for suffix of executables... Preprocessing library for ghc-boot-th-next-9.14...
Building library for ghc-boot-th-next-9.14...
checking build system type... Warning: this is a debug build of cabal-install with assertions enabled.

checking whether we are cross compiling... Preprocessing library for ghc-platform-0.1.0.0...
Building library for ghc-platform-0.1.0.0...
Warning: this is a debug build of cabal-install with assertions enabled.
x86_64-pc-linux-gnu
checking host system type... x86_64-pc-linux-gnu
checking target system type... x86_64-pc-linux-gnu
checking for gsed... sed
checking for gcc... /home/hsyl20/.ghc-wasm/wasi-sdk/bin/wasm32-wasi-clang
Preprocessing library for os-string-2.0.8...
Building library for os-string-2.0.8...
Warning: this is a debug build of cabal-install with assertions enabled.
configure: error: in '/home/hsyl20/projects/ghc/scratch/stable-wasm/ghc/_build/stage1/build/build/x86_64-linux/ghc-9.8.4/unix-2.8.8.0/build':
configure: error: cannot run C compiled programs.
If you meant to cross compile, use '--host'.
See 'config.log' for more details
Preprocessing library for rts-fs-1.0.0.0...
Building library for rts-fs-1.0.0.0...
checking whether the C compiler works... Preprocessing library for rts-headers-1.0.3...
Building library for rts-headers-1.0.3...
Warning: this is a debug build of cabal-install with assertions enabled.
yes
checking for C compiler default output file name... a.out
checking for suffix of executables... Warning: this is a debug build of cabal-install with assertions enabled.

checking whether we are cross compiling... configure: error: in '/home/hsyl20/projects/ghc/scratch/stable-wasm/ghc/_build/stage1/build/host/x86_64-linux/ghc-9.8.4/libffi-clib-3.5.2/build':
configure: error: cannot run C compiled programs.
If you meant to cross compile, use '--host'.
See 'config.log' for more details
Warning: this is a debug build of cabal-install with assertions enabled.
[ 2 of 13] Compiling GHC.Internal.ForeignSrcLang [/home/hsyl20/projects/ghc/scratch/stable-wasm/ghc/_build/stage1/build/host/x86_64-linux/ghc-9.8.4/ghc-boot-th-next-9.14/build/autogen/cabal_macros.h changed]
[ 1 of 11] Compiling System.OsString.Data.ByteString.Short.Internal [/home/hsyl20/projects/ghc/scratch/stable-wasm/ghc/_build/stage1/build/host/x86_64-linux/ghc-9.8.4/os-string-2.0.8/build/autogen/cabal_macros.h changed]
[ 4 of 13] Compiling GHC.Internal.LanguageExtensions [/home/hsyl20/projects/ghc/scratch/stable-wasm/ghc/_build/stage1/build/host/x86_64-linux/ghc-9.8.4/ghc-boot-th-next-9.14/build/autogen/cabal_macros.h changed]
[ 3 of 11] Compiling System.OsString.Data.ByteString.Short.Word16 [/home/hsyl20/projects/ghc/scratch/stable-wasm/ghc/_build/stage1/build/host/x86_64-linux/ghc-9.8.4/os-string-2.0.8/build/autogen/cabal_macros.h changed]
[ 7 of 11] Compiling System.OsString.Internal.Types [/home/hsyl20/projects/ghc/scratch/stable-wasm/ghc/_build/stage1/build/host/x86_64-linux/ghc-9.8.4/os-string-2.0.8/build/autogen/cabal_macros.h changed]
[ 5 of 13] Compiling GHC.Internal.Lexeme [/home/hsyl20/projects/ghc/scratch/stable-wasm/ghc/_build/stage1/build/host/x86_64-linux/ghc-9.8.4/ghc-boot-th-next-9.14/build/autogen/cabal_macros.h changed]
[ 6 of 13] Compiling GHC.Internal.TH.Syntax [/home/hsyl20/projects/ghc/scratch/stable-wasm/ghc/_build/stage1/build/host/x86_64-linux/ghc-9.8.4/ghc-boot-th-next-9.14/build/autogen/cabal_macros.h changed]
[ 8 of 11] Compiling System.OsString.Posix [/home/hsyl20/projects/ghc/scratch/stable-wasm/ghc/_build/stage1/build/host/x86_64-linux/ghc-9.8.4/os-string-2.0.8/build/autogen/cabal_macros.h changed]
[ 9 of 11] Compiling System.OsString.Internal [/home/hsyl20/projects/ghc/scratch/stable-wasm/ghc/_build/stage1/build/host/x86_64-linux/ghc-9.8.4/os-string-2.0.8/build/autogen/cabal_macros.h changed]
[11 of 11] Compiling System.OsString.Windows [/home/hsyl20/projects/ghc/scratch/stable-wasm/ghc/_build/stage1/build/host/x86_64-linux/ghc-9.8.4/os-string-2.0.8/build/autogen/cabal_macros.h changed]
Warning: this is a debug build of cabal-install with assertions enabled.
[ 7 of 13] Compiling GHC.Internal.TH.Lib [/home/hsyl20/projects/ghc/scratch/stable-wasm/ghc/_build/stage1/build/host/x86_64-linux/ghc-9.8.4/ghc-boot-th-next-9.14/build/autogen/cabal_macros.h changed]
[12 of 13] Compiling GHC.Lexeme [/home/hsyl20/projects/ghc/scratch/stable-wasm/ghc/_build/stage1/build/host/x86_64-linux/ghc-9.8.4/ghc-boot-th-next-9.14/build/autogen/cabal_macros.h changed]
Warning: this is a debug build of cabal-install with assertions enabled.
Error: [Cabal-7125]
Failed to configure build:unix-2.8.8.0. The failure occurred during the configure step. The build process terminated with exit code 77
Failed to configure host:libffi-clib-3.5.2 (which is required by exe:ghc from host:ghc-bin-9.14-ghc). The failure occurred during the configure step. The build process terminated with exit code 77
make: *** [Makefile:625: _build/stage1/bin/deriveConstants] Error 1

[hasufell]

It's using the wasm toolchain for building stage1, which it shouldn't do.

What's your environment?

[hsyl20]

ArchLinux / x86-64

[hasufell]

ArchLinux / x86-64

I meant env... :D

My suspicion is that CC and other variables are set and you sourced the whole ~/.ghc-wasm/env... but we must only use the PATH parts of said file.

[hsyl20]

Aah indeed. I followed the installation steps and source the original ~/.ghc-wasm/env before modifying it and sourcing it again. I've updated the build instructions

Now it's failing with:

Building executable 'ghc' for ghc-bin-9.14...
[1 of 3] Compiling GHC.Driver.Session.Mode [/home/hsyl20/projects/ghc/scratch/stable-wasm/ghc/_build/stage1/build/host/x86_64-linux/ghc-9.8.4/ghc-bin-9.14-ghc/build/ghc/autogen/cabal_macros.h changed]
[2 of 3] Compiling GHC.Driver.Session.Lint [/home/hsyl20/projects/ghc/scratch/stable-wasm/ghc/_build/stage1/build/host/x86_64-linux/ghc-9.8.4/ghc-bin-9.14-ghc/build/ghc/autogen/cabal_macros.h changed]
[3 of 3] Compiling Main [/home/hsyl20/projects/ghc/scratch/stable-wasm/ghc/_build/stage1/build/host/x86_64-linux/ghc-9.8.4/ghc-bin-9.14-ghc/build/ghc/autogen/cabal_macros.h changed]
[4 of 4] Linking /home/hsyl20/projects/ghc/scratch/stable-wasm/ghc/_build/stage1/build/host/x86_64-linux/ghc-9.8.4/ghc-bin-9.14-ghc/build/ghc/ghc [Objects changed]
ld.lld: error: /home/hsyl20/projects/ghc/scratch/stable-wasm/ghc/_build/stage1/build/host/x86_64-linux/ghc-9.8.4/libffi-clib-3.5.2/build/libHSlibffi-clib-3.5.2.a(win64.o):(.debug_frame) is compressed with ELFCOMPRESS_ZLIB, but lld is not built with zlib support
collect2: error: ld returned 1 exit status
ghc-9.8.4: `gcc' failed in phase `Linker'. (Exit code: 1)
Error: [Cabal-7125]
Failed to build exe:ghc from host:ghc-bin-9.14-ghc.
make: *** [Makefile:625: _build/stage1/bin/deriveConstants] Error 1

[hsyl20]

Maybe it's using a leftover file. I'll retry after deleting _build

Edit: same failure

[hasufell]

I think it's still using some wasm tools for stage1. It's really annoying that there are non-prefixed binaries shipped with wasm.

The easiest stop gap solution is to build stage2 as described earlier, remove the stage2 dependency from stage3 in the Makefile and then build stage3.

I'll see later if I can reproduce.

[hasufell]

I'm afraid I can't reproduce. It builds for me.

But I do the sourcing of wasm env before step 4.

My ~/.ghc-wasm/env is:

export PATH=/home/hasufell/.ghc-wasm/wasm-run/bin:$PATH
export PATH=/home/hasufell/.ghc-wasm/wasm32-wasi-cabal/bin:$PATH
export PATH=/home/hasufell/.ghc-wasm/wasmtime/bin:$PATH
export PATH=/home/hasufell/.ghc-wasm/binaryen/bin:$PATH
export PATH=/home/hasufell/.ghc-wasm/nodejs/bin:$PATH
export PATH=/home/hasufell/.ghc-wasm/wasi-sdk/bin:$PATH
export PATH=/home/hasufell/.ghc-wasm/wasm32-wasi-ghc/bin:$PATH

To double check, this is the bin directory (maybe I messed around with it?):

$ /bin/ls -l /home/hasufell/.ghc-wasm/wasi-sdk/bin
total 351456
lrwxrwxrwx 1 hasufell hasufell        7 Nov 16  2024 ar -> llvm-ar
lrwxrwxrwx 1 hasufell hasufell       12 Nov 16  2024 c++filt -> llvm-cxxfilt
lrwxrwxrwx 1 hasufell hasufell        8 Nov 16  2024 clang -> clang-19
lrwxrwxrwx 1 hasufell hasufell        5 Nov 16  2024 clang++ -> clang
-rwxr-xr-x 1 hasufell hasufell 99382864 Nov 16  2024 clang-19
-rwxr-xr-x 1 hasufell hasufell  3655552 Nov 16  2024 clang-apply-replacements
lrwxrwxrwx 1 hasufell hasufell        5 Nov 16  2024 clang-cl -> clang
lrwxrwxrwx 1 hasufell hasufell        5 Nov 16  2024 clang-cpp -> clang
-rwxr-xr-x 1 hasufell hasufell  4106784 Nov 16  2024 clang-format
-rwxr-xr-x 1 hasufell hasufell 63344000 Nov 16  2024 clang-tidy
-rwxr-xr-x 1 hasufell hasufell    25747 Nov 16  2024 git-clang-format
lrwxrwxrwx 1 hasufell hasufell        3 Nov 16  2024 ld64.lld -> lld
lrwxrwxrwx 1 hasufell hasufell        3 Nov 16  2024 ld.lld -> lld
-rwxr-xr-x 1 hasufell hasufell 40918800 Nov 16  2024 llc
-rwxr-xr-x 1 hasufell hasufell 46634608 Nov 16  2024 lld
lrwxrwxrwx 1 hasufell hasufell        3 Nov 16  2024 lld-link -> lld
-rwxr-xr-x 1 hasufell hasufell  5354592 Nov 16  2024 llvm-ar
-rwxr-xr-x 1 hasufell hasufell   512880 Nov 16  2024 llvm-config
-rwxr-xr-x 1 hasufell hasufell  1140432 Nov 16  2024 llvm-cxxfilt
-rwxr-xr-x 1 hasufell hasufell  5866784 Nov 16  2024 llvm-dwarfdump
-rwxr-xr-x 1 hasufell hasufell 20561936 Nov 16  2024 llvm-dwp
-rwxr-xr-x 1 hasufell hasufell  2369568 Nov 16  2024 llvm-mc
-rwxr-xr-x 1 hasufell hasufell  6404000 Nov 16  2024 llvm-nm
-rwxr-xr-x 1 hasufell hasufell  5542240 Nov 16  2024 llvm-objcopy
-rwxr-xr-x 1 hasufell hasufell  7867712 Nov 16  2024 llvm-objdump
lrwxrwxrwx 1 hasufell hasufell        7 Nov 16  2024 llvm-ranlib -> llvm-ar
-rwxr-xr-x 1 hasufell hasufell  4798496 Nov 16  2024 llvm-size
-rwxr-xr-x 1 hasufell hasufell   500240 Nov 16  2024 llvm-strings
lrwxrwxrwx 1 hasufell hasufell       12 Nov 16  2024 llvm-strip -> llvm-objcopy
lrwxrwxrwx 1 hasufell hasufell        7 Nov 16  2024 nm -> llvm-nm
lrwxrwxrwx 1 hasufell hasufell       12 Nov 16  2024 objcopy -> llvm-objcopy
lrwxrwxrwx 1 hasufell hasufell       12 Nov 16  2024 objdump -> llvm-objdump
-rwxr-xr-x 1 hasufell hasufell 40811152 Nov 16  2024 opt
lrwxrwxrwx 1 hasufell hasufell        7 Nov 16  2024 ranlib -> llvm-ar
-rwxr-xr-x 1 hasufell hasufell    19711 Nov 16  2024 run-clang-tidy
lrwxrwxrwx 1 hasufell hasufell        9 Nov 16  2024 size -> llvm-size
lrwxrwxrwx 1 hasufell hasufell       12 Nov 16  2024 strings -> llvm-strings
lrwxrwxrwx 1 hasufell hasufell       12 Nov 16  2024 strip -> llvm-objcopy
lrwxrwxrwx 1 hasufell hasufell        5 Nov 16  2024 wasm32-wasi-clang -> clang
lrwxrwxrwx 1 hasufell hasufell        5 Nov 16  2024 wasm32-wasi-clang++ -> clang
-rwxr-xr-x 1 hasufell hasufell      185 Aug 13 21:15 wasm32-wasi-clangg
lrwxrwxrwx 1 hasufell hasufell        7 Aug 20 19:23 wasm32-wasi-nm -> llvm-nm
lrwxrwxrwx 1 hasufell hasufell        5 Nov 16  2024 wasm32-wasip1-clang -> clang
lrwxrwxrwx 1 hasufell hasufell        5 Nov 16  2024 wasm32-wasip1-clang++ -> clang
lrwxrwxrwx 1 hasufell hasufell        5 Nov 16  2024 wasm32-wasip1-threads-clang -> clang
lrwxrwxrwx 1 hasufell hasufell        5 Nov 16  2024 wasm32-wasip1-threads-clang++ -> clang
lrwxrwxrwx 1 hasufell hasufell        5 Nov 16  2024 wasm32-wasip2-clang -> clang
lrwxrwxrwx 1 hasufell hasufell        5 Nov 16  2024 wasm32-wasip2-clang++ -> clang
lrwxrwxrwx 1 hasufell hasufell        5 Nov 16  2024 wasm32-wasi-threads-clang -> clang
lrwxrwxrwx 1 hasufell hasufell        5 Nov 16  2024 wasm32-wasi-threads-clang++ -> clang
lrwxrwxrwx 1 hasufell hasufell        3 Nov 16  2024 wasm-ld -> lld
-rwxr-xr-x 1 hasufell hasufell       91 Aug 13 19:53 wasm-ldd

[hsyl20]

Maybe your ld.lld is built with zlib support but not mine?

[hasufell]

I use ld.bfd.

[hasufell]

Maybe your ld.lld is built with zlib support but not mine?

Well, the wasm provided ld.lld doesn't (afair)... so maybe it's picking that up. But that would only be the case if you set LD=ld.lld in your environment.