Troubleshooting your build

(on Linux)
error: getting status of /nix/var/nix/daemon-socket/socket: Permission denied

If you get this error and you’ve installed Nix with your system package manager:

  • Add yourself to the nix-users group
  • Log out and log back in
(on Linux)
error: file 'nixpkgs' was not found in the Nix search path (add it using $NIX_PATH or -I)

This error is harmless, but you can fix it as follows:

  • Run sudo nix-channel --add nixpkgs
  • Run sudo nix-channel --update
(on Windows)
Cannot run mach in a path on a case-sensitive file system on Windows.
  • Open a command prompt or PowerShell as administrator (Win+X, A)
  • Disable case sensitivity for your Servo repo:
    fsutil file SetCaseSensitiveInfo X:\path\to\servo disable
(on Windows)
Could not find DLL dependency: api-ms-win-crt-runtime-l1-1-0.dll
DLL file `api-ms-win-crt-runtime-l1-1-0.dll` not found!

Find the path to Redist\ucrt\DLLs\x64\api-ms-win-crt-runtime-l1-1-0.dll, e.g. C:\Program Files (x86)\Windows Kits\10\Redist\ucrt\DLLs\x64\api-ms-win-crt-runtime-l1-1-0.dll.

Then set the WindowsSdkDir environment variable to the path that contains Redist, e.g. C:\Program Files (x86)\Windows Kits\10.

(on Windows)
thread 'main' panicked at 'Unable to find libclang: "couldn\'t find any valid shared libraries matching: [\'clang.dll\', \'libclang.dll\'], set the `LIBCLANG_PATH` environment variable to a path where one of these files can be found (invalid: [(C:\\Program Files\\LLVM\\bin\\libclang.dll: invalid DLL (64-bit))])"', C:\Users\me\.cargo\registry\src\...

rustup may have been installed with the 32-bit default host, rather than the 64-bit default host needed by Servo. Check your default host with rustup show, then set the default host:

> rustup set default-host x86_64-pc-windows-msvc

(on Windows)
ERROR: GetShortPathName returned a long path name: `C:/PROGRA~2/Windows Kits/10/`. Use `fsutil file setshortname' to create a short name for any components of this path that have spaces.

SpiderMonkey (mozjs) requires 8.3 filenames to be enabled on Windows (#26010).

  • Open a command prompt or PowerShell as administrator (Win+X, A)
  • Enable 8.3 filename generation: fsutil behavior set disable8dot3 0
  • Uninstall and reinstall whatever contains the failing paths, such as Visual Studio or the Windows SDK — this is easier than adding 8.3 filenames by hand