Fixes https://github.com/zed-industries/zed/issues/24880
# Objective
"Assisted/analysed by AI"
> The remote_server musl build failed with undefined references to
__isoc23_sscanf and __isoc23_strtol from aws-lc-sys because the default
C compiler used glibc headers while linking against musl libc. Setting
CC_<target>=musl-gcc ensures C dependencies compile with musl headers.
I have tested the fix, and it seems to have fixed the compilation issue
I faced on Fedora 44, without resorting to the [hack noted in
docs](https://zed.dev/docs/development/linux#installing-a-development-build).
Initially reported in this
[issue](https://github.com/zed-industries/zed/issues/24880).
I'd want someone with expertise in the domain to take a look at this
fix, as from what I understand, the process in the doc is a hacky
workaround.
## Solution
Setting CC_<target>=musl-gcc ensures C dependencies compile with musl
headers.
## Testing
- Did you test these changes? If so, how?
<details><summary>Here's my steps to repro:</summary>
1. install [toolbox](https://github.com/containers/toolbox) (or
podman-toolbox)
(I used toolbox as it's easy to reuse the cloned repo, as the whole home
dir is mounted in the devcontainer)
Used the main branch - commit 5d6c88cdb7
2. toolbox create -d fedora -r 44
3. toolbox enter fedora-toolbox-44
4. then run the `scripts/linux` script to install prereqs
5. try compiling remote-server using the commands in
`scripts/install-linux` (I just ran the script wholly)
LDD version:
```
⬢[root@toolbox zed]# ldd --version
ldd (GNU libc) 2.43
```
GCC/MUSL versions:
```
musl-gcc : 1.2.5
gcc : 16.1.1
```
Error:
```
error: linking with `cc` failed: exit status: 1
|
= note: "cc" "-m64"
"<sysroot>/lib/rustlib/x86_64-unknown-linux-musl/lib/self-contained/rcrt1.o"
"<sysroot>/lib/rustlib/x86_64-unknown-linux-musl/lib/self-contained/crti.o"
"<sysroot>/lib/rustlib/x86_64-unknown-linux-musl/lib/self-contained/crtbeginS.o"
"<747 object files omitted>" "-Wl,--as-needed" "-Wl,-Bstatic"
"/root/zed/target/x86_64-unknown-linux-musl/release/deps/rustceHhjo8/{libzstd_sys-5c3eb6739555ecf4,libtree_sitter_json-ad90c8af7e8a3750,libtree_sitter-f91a92b688e12e56,libwasmtime-decd3377028506ce,libaws_lc_sys-a051f708b6dafc2a,libring-fcc1b43e3092bc93,libpsm-d967f50c6f2b67a4}.rlib"
"-lunwind" "-lc"
"<sysroot>/lib/rustlib/x86_64-unknown-linux-musl/lib/libcompiler_builtins-*.rlib"
"-L"
"/root/zed/target/x86_64-unknown-linux-musl/release/deps/rustceHhjo8/raw-dylibs"
"-Wl,-Bdynamic" "-Wl,--eh-frame-hdr" "-Wl,-z,noexecstack"
"-nostartfiles" "-L"
"/root/zed/target/x86_64-unknown-linux-musl/release/build/psm-dc603221f407eabc/out"
"-L"
"/root/zed/target/x86_64-unknown-linux-musl/release/build/tree-sitter-28f7b87c1db3fab9/out"
"-L"
"/root/zed/target/x86_64-unknown-linux-musl/release/build/wasmtime-f0bb0950e09a7352/out"
"-L"
"/root/zed/target/x86_64-unknown-linux-musl/release/build/aws-lc-sys-2a7ca8eafafe18fa/out"
"-L"
"/root/zed/target/x86_64-unknown-linux-musl/release/build/ring-d7857a166bac60a6/out"
"-L"
"/root/zed/target/x86_64-unknown-linux-musl/release/build/zstd-sys-0e04609af7157148/out"
"-L"
"/root/zed/target/x86_64-unknown-linux-musl/release/build/tree-sitter-json-b1e2eeaba7bbb519/out"
"-L"
"<sysroot>/lib/rustlib/x86_64-unknown-linux-musl/lib/self-contained"
"-L" "<sysroot>/lib/rustlib/x86_64-unknown-linux-musl/lib" "-o"
"/root/zed/target/x86_64-unknown-linux-musl/release/deps/remote_server-3782b255c59d4e14"
"-Wl,--gc-sections" "-static-pie" "-Wl,-z,relro,-z,now" "-Wl,-O1"
"-nodefaultlibs" "-Wl,--disable-new-dtags,-rpath,$ORIGIN/../lib"
"<sysroot>/lib/rustlib/x86_64-unknown-linux-musl/lib/self-contained/crtendS.o"
"<sysroot>/lib/rustlib/x86_64-unknown-linux-musl/lib/self-contained/crtn.o"
= note: some arguments are omitted. use `--verbose` to show all linker
arguments
= note: /usr/bin/ld.bfd:
/root/zed/target/x86_64-unknown-linux-musl/release/deps/rustceHhjo8/libaws_lc_sys-a051f708b6dafc2a.rlib(f8e4fd781484bd36-bcm.o):
in function `aws_lc_0_40_0_handle_cpu_env':
/aws-lc/crypto/fipsmodule/cpucap/cpu_intel.c:(.text.aws_lc_0_40_0_handle_cpu_env+0x63):
undefined reference to `__isoc23_sscanf'
/usr/bin/ld.bfd:
/root/zed/target/x86_64-unknown-linux-musl/release/deps/rustceHhjo8/libaws_lc_sys-a051f708b6dafc2a.rlib(f8e4fd781484bd36-bcm.o):
in function `pkey_rsa_ctrl_str':
/aws-lc/crypto/fipsmodule/evp/p_rsa.c:692:(.text.pkey_rsa_ctrl_str+0x222):
undefined reference to `__isoc23_strtol'
/usr/bin/ld.bfd:
/aws-lc/crypto/fipsmodule/evp/p_rsa.c:703:(.text.pkey_rsa_ctrl_str+0x261):
undefined reference to `__isoc23_strtol'
collect2: error: ld returned 1 exit status
= note: some `extern` functions couldn't be found; some native libraries
may need to be installed or have their path specified
= note: use the `-l` flag to specify native libraries to link
= note: use the `cargo:rustc-link-lib` directive to specify the native
libraries to link with Cargo (see
https://doc.rust-lang.org/cargo/reference/build-scripts.html#rustc-link-lib)
error: could not compile `remote_server` (bin "remote_server") due to 1
previous error
```
</details>
- Are there any parts that need more testing? -- Maybe
- How can other people (reviewers) test your changes? Is there anything
specific they need to know? -- Steps listed above
- If relevant, what platforms did you test these changes on, and are
there any important ones you can't test? -- Fedora 44
## Self-Review Checklist:
- [x] I've reviewed my own diff for quality, security, and reliability
- [x] Unsafe blocks (if any) have justifying comments
- [x] The content adheres to Zed's UI standards
([UX/UI](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)
and
[icon](https://github.com/zed-industries/zed/blob/main/crates/icons/README.md)
guidelines)
- [ ] Tests cover the new/changed behavior
- [ ] Performance impact has been considered and is acceptable
## Showcase
> This section is optional. If this PR does not include a visual change
or does not add a new user-facing feature, you can delete this section.
- Help others understand the result of this PR by showcasing your
awesome work!
- If this PR includes a visual change, consider adding a screenshot,
GIF, or video
- A before/after comparison is very useful for changes to existing
features!
While a showcase should aim to be brief and digestible, you can use a
toggleable section to save space on longer showcases:
<details>
<summary>Click to view showcase</summary>
My super cool demos here
</details>
---
Release Notes:
- Fixed musl error when building remote server from source for the
default musl triple on Linux
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
9aa48e46e9