tailwindlabs/tailwindcss · error · Error

Unsupported libc on: ${process.platform}-${process.arch}

Error message

Unsupported libc on: ${process.platform}-${process.arch}

What it means

Patched into @parcel/watcher's native-binding loader. The patch uses detect-libc's familySync() to pick a platform/arch-specific binary; if the detected libc family is neither MUSL nor GLIBC (e.g. a BSD libc, or an unrecognized environment), it throws. This replaces upstream logic that assumed glibc-style suffixes.

Source

Thrown at patches/@parcel__watcher@2.6.0.patch:58

-      binding = require('./build/Debug/watcher.node');
-    } catch (err) {
-      handleError(err);
-      throw new Error(
-        `No prebuild or local build of @parcel/watcher found. Tried ${name}. Please ensure it is installed (don't use --no-optional when installing with npm). Otherwise it is possible we don't support your platform yet. If this is the case, please report an issue to https://github.com/parcel-bundler/watcher.`,
-      );
-    }
-  }
-}
 
-function handleError(err) {
-  if (err?.code !== 'MODULE_NOT_FOUND') {
-    throw err;
+      if (family === MUSL) {
+        return require(`@parcel/watcher-${process.platform}-${process.arch}-musl`)
+      } else if (family === GLIBC) {
+        return require(`@parcel/watcher-${process.platform}-${process.arch}-glibc`)
+      } else {
+        throw new Error(`Unsupported libc on: ${process.platform}-${process.arch}`)
+      }
+    }
+  } else {
+    return require(`@parcel/watcher-${process.platform}-${process.arch}`)
   }
 }
 
-const wrapper = createWrapper(binding);
+const wrapper = createWrapper(loadPackage());
 exports.writeSnapshot = wrapper.writeSnapshot;
 exports.getEventsSince = wrapper.getEventsSince;
 exports.subscribe = wrapper.subscribe;

View on GitHub (pinned to 16e94cbf7f)

Solutions

1. Verify your libc: run 'ldd --version' or 'node -e "console.log(require('detect-libc').familySync())"'.
2. Preinstall the correct platform-specific binary package directly (e.g. @parcel/watcher-linux-x64-gnu).
3. Update detect-libc to a version that recognizes your environment.
4. If on a truly unsupported libc, switch to a polling-based file watcher or a glibc/musl container.

Example fix

# before — detect-libc returns UNKNOWN, patch throws
# (no code fix; environment fix)

# after — pin the correct binary package
npm i @parcel/watcher-linux-x64-glibc --build-from-source=false

const { familySync, MUSL, GLIBC } = require('detect-libc')
const family = familySync()
if (family !== MUSL && family !== GLIBC) {
  throw new Error(`Unsupported libc family: ${family} — install the binary manually`)
}

function isSupportedLibc(family: string | null): boolean {
  return family === 'musl' || family === 'glibc'
}

try {
  require('@parcel/watcher')
} catch (e) {
  if (/Unsupported libc/.test(e.message)) {
    // fall back to a polling watcher
  }
}

When it happens

Trigger: Running @parcel/watcher on a platform where detect-libc returns a family other than MUSL or GLIBC. Non-Linux platforms normally skip this branch (the else at the bottom requires the default binding), so this fires on unusual Linux/libc combinations or environments where familySync misreports.

Common situations: Building/running in an exotic container or musl/glibc hybrid. A locked-down CI sandbox where detect-libc cannot read ld.so and returns unknown. Cross-compilation targets. A broken detect-libc version returning an unexpected family constant.

Related errors

• Unsupported libc on: ${process.platform}-${process.arch}
• unsupported platform
• walkdir: same_file_system option not supported on this platf

AI-assisted analysis of tailwindlabs/tailwindcss@16e94cbf7f (2026-08-12). Data as JSON: /api/errors/cfbbd9c7af63e9c9. Report an issue: GitHub.