Fix libc detection on various platforms (#6840)

## What's the problem this PR addresses?

Two problems:

1. #6170 broke `libc` detection on at least Alpine Linux and Chimera
Linux (and probably on all other `musl`-based distributions as well) by
looking for the generic string `libc` in `/usr/bin/ldd`. On both Chimera
and Alpine, `ldd --version` prints `musl libc` among the output.

2. `getLibc()` was doing unnecessary work on OSes other than Windows,
Mac, and Linux (I originally thought it would have been crashing, but
that's incorrect). ~~It strongly appears to me that `getLibc()` would
throw an error on any OS other than Windows, Mac, and Linux, as the
other OSes supported by node have their own libc implementations that
are neither `glibc` nor `musl`.~~
...

## How did you fix it?

1. The strings `GNU libc` and `GNU C Library` are searched for instead
of just `libc`.
* By default, `ldd` contains the text `GNU libc` in its `--version`
output, but that can be easily customized at build time using a build
configuration option (see
[here](https://github.com/bminor/glibc/blob/632d895f3e5d98162f77b9c3c1da4ec19968b671/elf/ldd.bash.in#L37)
and
[here](https://github.com/bminor/glibc/blob/632d895f3e5d98162f77b9c3c1da4ec19968b671/INSTALL#L273-L278)).
As a fallback, the text `GNU C Library` is found in the header of the
`ldd` script, and it will probably remain there as long as that file
remains a script (as opposed to a compiled binary).

2. I made `getLibc()` immediately return `null` on all non-Linux
platforms (not just Windows and macOS).

...

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Author: ItsHarper

.yarn/versions/1f924e2c.yml

@@ -0,0 +1,35 @@
+releases:
+  "@yarnpkg/core": patch
+  "@yarnpkg/cli": patch
+
+declined:
+  - "@yarnpkg/plugin-compat"
+  - "@yarnpkg/plugin-constraints"
+  - "@yarnpkg/plugin-dlx"
+  - "@yarnpkg/plugin-essentials"
+  - "@yarnpkg/plugin-exec"
+  - "@yarnpkg/plugin-file"
+  - "@yarnpkg/plugin-git"
+  - "@yarnpkg/plugin-github"
+  - "@yarnpkg/plugin-http"
+  - "@yarnpkg/plugin-init"
+  - "@yarnpkg/plugin-interactive-tools"
+  - "@yarnpkg/plugin-jsr"
+  - "@yarnpkg/plugin-link"
+  - "@yarnpkg/plugin-nm"
+  - "@yarnpkg/plugin-npm"
+  - "@yarnpkg/plugin-npm-cli"
+  - "@yarnpkg/plugin-pack"
+  - "@yarnpkg/plugin-patch"
+  - "@yarnpkg/plugin-pnp"
+  - "@yarnpkg/plugin-pnpm"
+  - "@yarnpkg/plugin-stage"
+  - "@yarnpkg/plugin-typescript"
+  - "@yarnpkg/plugin-version"
+  - "@yarnpkg/plugin-workspace-tools"
+  - "@yarnpkg/builder"
+  - "@yarnpkg/doctor"
+  - "@yarnpkg/extensions"
+  - "@yarnpkg/nm"
+  - "@yarnpkg/pnpify"
+  - "@yarnpkg/sdks"

packages/yarnpkg-core/sources/nodeUtils.ts

@@ -26,9 +26,10 @@ export const openUrl = typeof openUrlBinary !== `undefined`
 const LDD_PATH = `/usr/bin/ldd` as PortablePath;
 
 function getLibc() {
-  // Darwin and Windows have their own standard libraries, and the getReport() call is costly.
-  // It also seems that Node randomly crashes with no output under some circumstances when running a getReport() on Windows.
-  if (process.platform === `darwin` || process.platform === `win32`)
+  // As of 2025, linux is the only possible process.platform value that does not imply the libc for Node's purposes.
+  // Technically mingw32 (a way to build and run software using glibc on Windows) exists and even has a node.js port, but no one in
+  // the broader node.js ecosystem seems to care about it. There have been issues in the past running getReport() on Windows.
+  if (process.platform !== `linux`)
     return null;
 
   let header: Buffer | undefined;
@@ -39,7 +40,7 @@ function getLibc() {
   // Since the getReport can be prohibitely expensive (it also queries DNS which, if misconfigured, can take a long time to timeout),
   // we first check if the ldd binary is glibc or musl, and only then run the getReport() if we can't determine the libc variant.
   if (typeof header !== `undefined`) {
-    if (header && (header.includes(`GLIBC`) || header.includes(`libc`)))
+    if (header && (header.includes(`GLIBC`) || header.includes(`GNU libc`) || header.includes(`GNU C Library`)))
       return `glibc`;
     if (header && header.includes(`musl`)) {
       return `musl`;