fn addInstallDirDefaultNull(wc: *Configuration.Wip, install_dir: ?std.Build.InstallDir) !?Configuration.InstallDestDir
fn addInstallDirDefaultNull(wc: *Configuration.Wip, install_dir: ?std.Build.InstallDir) !?Configuration.InstallDestDir { return try addInstallDir(wc, install_dir orelse return null); }