useShellEnv: don't auto-export lib/ for libc-style bottles

fixtures/projects/curl.se/package.yml

@@ -0,0 +1,2 @@
+provides:
+  - bin/curl

fixtures/projects/gnu.org/glibc/package.yml

@@ -0,0 +1,4 @@
+provides:
+  - bin/getconf
+platforms:
+  - linux

src/hooks/useShellEnv.test.ts

@@ -1,4 +1,4 @@
-import { assertEquals } from "@std/assert"
+import { assertEquals, assert } from "@std/assert"
 import { useTestConfig } from "./useTestConfig.ts"
 import useShellEnv from "./useShellEnv.ts"
 import SemVer from "../utils/semver.ts"
@@ -24,3 +24,37 @@ Deno.test("useShellEnv", async () => {
 
   assertEquals(env.PATH, `${installations[0].path.join("bin")}${SEP}${installations[1].path.join("bin")}`)
 })
+
+Deno.test("useShellEnv: gnu.org/glibc does not export lib/ to LIBRARY_PATH", async () => {
+  // Regression test for libc-style bottles polluting consumers'
+  // LD_LIBRARY_PATH and breaking the host's coreutils.
+  const { map } = useShellEnv()
+  const { prefix } = useTestConfig()
+
+  const glibc_install = {
+    pkg: { project: 'gnu.org/glibc', version: new SemVer('2.43.0') },
+    path: prefix.join("gnu.org/glibc/v2.43.0"),
+  }
+  const curl_install = {
+    pkg: { project: 'curl.se', version: new SemVer('8.13.0') },
+    path: prefix.join("curl.se/v8.13.0"),
+  }
+
+  // Both bottles have a populated lib/ directory.
+  glibc_install.path.join("lib").mkdir('p')
+  curl_install.path.join("lib").mkdir('p')
+
+  const vars = await map({ installations: [glibc_install, curl_install] })
+
+  // curl's lib/ is still exposed (existing behaviour).
+  const lib_paths = vars.LIBRARY_PATH ?? []
+  assert(
+    lib_paths.some(p => p.endsWith("curl.se/v8.13.0/lib")),
+    `expected curl's lib/ in LIBRARY_PATH, got: ${lib_paths.join(", ")}`,
+  )
+  // glibc's lib/ is NOT — that's the new opt-out behaviour.
+  assert(
+    !lib_paths.some(p => p.endsWith("gnu.org/glibc/v2.43.0/lib")),
+    `glibc's lib/ should not be in LIBRARY_PATH, got: ${lib_paths.join(", ")}`,
+  )
+})

src/hooks/useShellEnv.ts

@@ -19,6 +19,21 @@ export const EnvKeys = [
 ] as const
 export type EnvKey = typeof EnvKeys[number]
 
+/// Projects whose `lib/` MUST NOT be auto-added to LIBRARY_PATH /
+/// LD_LIBRARY_PATH for consumers, because their `lib/` *is* the libc
+/// (libc.so.6, libm.so.6, ld-linux*.so) — adding it to consumers'
+/// dynamic-linker search path forces every executable in the same
+/// pkgx env to load this bottle's libc, which fails the moment the
+/// host's own ld-linux is older than what the bottle's libc requires.
+///
+/// This set lists projects that legitimately ship libc itself. It is
+/// intentionally small and hardcoded; long-term the per-package opt
+/// should be expressed in the bottle's own metadata so the pantry
+/// doesn't need a coordinated libpkgx release for new entries.
+const NO_LIB_EXPORT: ReadonlySet<string> = new Set([
+  'gnu.org/glibc',
+])
+
 interface Options {
   installations: Installation[]
 }
@@ -55,7 +70,14 @@ async function map({installations}: Options): Promise<Record<string, string[]>>
       }
     }
 
-    if (archaic) {
+    // libc-style projects (see NO_LIB_EXPORT) MUST NOT have their
+    // lib/ added to LIBRARY_PATH / LD_LIBRARY_PATH: adding a glibc
+    // bottle's lib/ to LD_LIBRARY_PATH would force every executable
+    // in the same pkgx env to load THIS bottle's libc.so.6, which
+    // breaks on hosts whose own ld-linux is older than the bottle's
+    // libc requires. Also skip the CPATH/include auto-add for the
+    // same reason (compile-time vs runtime libc skew).
+    if (archaic && !NO_LIB_EXPORT.has(installation.pkg.project)) {
       vars.LIBRARY_PATH = compact_add(vars.LIBRARY_PATH, installation.path.join("lib").chuzzle()?.string)
       vars.CPATH = compact_add(vars.CPATH, installation.path.join("include").chuzzle()?.string)
     }