diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/libstore/globals.cc | 25 |
1 files changed, 24 insertions, 1 deletions
diff --git a/src/libstore/globals.cc b/src/libstore/globals.cc index 32e9a6ea9..d53377239 100644 --- a/src/libstore/globals.cc +++ b/src/libstore/globals.cc @@ -77,7 +77,30 @@ Settings::Settings() allowedImpureHostPrefixes = tokenizeString<StringSet>("/System/Library /usr/lib /dev /bin/sh"); #endif - buildHook = getSelfExe().value_or("nix") + " __build-remote"; + /* Set the build hook location + + For builds we perform a self-invocation, so Nix has to be self-aware. + That is, it has to know where it is installed. We don't think it's sentient. + + Normally, nix is installed according to `nixBinDir`, which is set at compile time, + but can be overridden. This makes for a great default that works even if this + code is linked as a library into some other program whose main is not aware + that it might need to be a build remote hook. + + However, it may not have been installed at all. For example, if it's a static build, + there's a good chance that it has been moved out of its installation directory. + That makes `nixBinDir` useless. Instead, we'll query the OS for the path to the + current executable, using `getSelfExe()`. + + As a last resort, we resort to `PATH`. Hopefully we find a `nix` there that's compatible. + If you're porting Nix to a new platform, that might be good enough for a while, but + you'll want to improve `getSelfExe()` to work on your platform. + */ + std::string nixExePath = nixBinDir + "/nix"; + if (!pathExists(nixExePath)) { + nixExePath = getSelfExe().value_or("nix"); + } + buildHook = nixExePath + " __build-remote"; } void loadConfFile() |