diff options
Diffstat (limited to 'src/libstore/build.cc')
| -rw-r--r-- | src/libstore/build.cc | 23 |
1 files changed, 20 insertions, 3 deletions
diff --git a/src/libstore/build.cc b/src/libstore/build.cc index e6a3a4156699..278529bc22c1 100644 --- a/src/libstore/build.cc +++ b/src/libstore/build.cc @@ -1203,12 +1203,29 @@ void DerivationGoal::startBuilder() derivation, tell the builder, so that for instance `fetchurl' can skip checking the output. On older Nixes, this environment variable won't be set, so `fetchurl' will do the check. */ + bool fixedOutput = true; for (DerivationOutputs::iterator i = drv.outputs.begin(); i != drv.outputs.end(); ++i) - if (i->second.hash != "") - env["NIX_OUTPUT_CHECKED"] = "1"; - + if (i->second.hash == "") fixedOutput = false; + if (fixedOutput) + env["NIX_OUTPUT_CHECKED"] = "1"; + + /* *Only* if this is a fixed-output derivation, propagate the + values of the environment variables specified in the + `impureEnvVars' attribute to the builder. This allows for + instance environment variables for proxy configuration such as + `http_proxy' to be easily passed to downloaders like + `fetchurl'. Passing such environment variables from the caller + to the builder is generally impure, but the output of + fixed-output derivations is by definition pure (since we + already know the cryptographic hash of the output). */ + if (fixedOutput) { + Strings varNames = tokenizeString(drv.env["impureEnvVars"]); + for (Strings::iterator i = varNames.begin(); i != varNames.end(); ++i) + env[*i] = getEnv(*i); + } + /* If we are running as root, and the `build-allow-root' setting is `false', then we have to build as one of the users listed in `build-users'. */ |