diff options
| author | Eelco Dolstra <eelco.dolstra@logicblox.com> | 2012-11-27T14·01+0100 |
|---|---|---|
| committer | Eelco Dolstra <eelco.dolstra@logicblox.com> | 2012-11-27T14·01+0100 |
| commit | 6c98e6a5dec2bcbc25ddeb2c279aa4a0b274bd6a (patch) | |
| tree | 2ef5df17cd5fc359c27f96adb3279deb791591a9 /src/libexpr/eval.cc | |
| parent | 8b8ee53bc73769bb25d967ba259dabc9b23e2e6f (diff) | |
Optionally ignore null-valued derivation attributes
This allows adding attributes like attr = if stdenv.system == "bla" then something else null; without changing the resulting derivation on non-<bla> platforms. We once considered adding a special "ignore" value for this purpose, but using null seems more elegant.
Diffstat (limited to 'src/libexpr/eval.cc')
| -rw-r--r-- | src/libexpr/eval.cc | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc index 31aaad5485f0..9eb5fc758985 100644 --- a/src/libexpr/eval.cc +++ b/src/libexpr/eval.cc @@ -139,6 +139,7 @@ EvalState::EvalState() , sSystem(symbols.create("system")) , sOverrides(symbols.create("__overrides")) , sOutputName(symbols.create("outputName")) + , sIgnoreNulls(symbols.create("__ignoreNulls")) , baseEnv(allocEnv(128)) , baseEnvDispl(0) , staticBaseEnv(false, 0) |