* Negative caching, i.e. caching of build failures. Disabled by

  default.  This is mostly useful for Hydra.

3 files changed, 45 insertions, 1 deletions

diff --git a/tests/Makefile.am b/tests/Makefile.am
index a16051f73510..beb7852db31c 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -7,7 +7,7 @@ TESTS = init.sh hash.sh lang.sh add.sh simple.sh dependencies.sh \
   fallback.sh nix-push.sh gc.sh gc-concurrent.sh verify.sh nix-pull.sh \
   referrers.sh user-envs.sh logging.sh nix-build.sh misc.sh fixed.sh \
   gc-runtime.sh install-package.sh check-refs.sh filter-source.sh \
-  remote-store.sh export.sh export-graph.sh
+  remote-store.sh export.sh export-graph.sh negative-caching.sh
 
 XFAIL_TESTS =
 
@@ -30,5 +30,6 @@ EXTRA_DIST = $(TESTS) \
   check-refs.nix \
   filter-source.nix \
   export-graph.nix \
+  negative-caching.nix \
   $(wildcard lang/*.nix) $(wildcard lang/*.exp) $(wildcard lang/*.exp.xml) $(wildcard lang/*.flags) \
   common.sh.in
diff --git a/tests/negative-caching.nix b/tests/negative-caching.nix
new file mode 100644
index 000000000000..10df67a748fc
--- /dev/null
+++ b/tests/negative-caching.nix
@@ -0,0 +1,21 @@
+with import ./config.nix;
+
+rec {
+
+  fail = mkDerivation {
+    name = "fail";
+    builder = builtins.toFile "builder.sh" "echo FAIL; exit 1";
+  };
+
+  succeed = mkDerivation {
+    name = "succeed";
+    builder = builtins.toFile "builder.sh" "echo SUCCEED; mkdir $out";
+  };
+
+  depOnFail = mkDerivation {
+    name = "dep-on-fail";
+    builder = builtins.toFile "builder.sh" "echo URGH; mkdir $out";
+    inputs = [fail succeed];
+  };
+
+}
diff --git a/tests/negative-caching.sh b/tests/negative-caching.sh
new file mode 100644
index 000000000000..e618e9443ef2
--- /dev/null
+++ b/tests/negative-caching.sh
@@ -0,0 +1,22 @@
+source common.sh
+
+clearStore
+
+set +e
+
+opts="--option build-cache-failure true --print-build-trace"
+
+# This build should fail, and the failure should be cached.
+log=$($nixbuild $opts negative-caching.nix -A fail 2>&1) && fail "should fail"
+echo "$log" | grep -q "@ build-failed" || fail "no build-failed trace"
+
+# Do it again.  The build shouldn't be tried again.
+log=$($nixbuild $opts negative-caching.nix -A fail 2>&1) && fail "should fail"
+echo "$log" | grep -q "FAIL" && fail "failed build not cached"
+echo "$log" | grep -q "@ build-failed .* cached" || fail "trace doesn't say cached"
+
+# Check that --keep-going works properly with cached failures.
+log=$($nixbuild $opts --keep-going negative-caching.nix -A depOnFail 2>&1) && fail "should fail"
+echo "$log" | grep -q "FAIL" && fail "failed build not cached (2)"
+echo "$log" | grep -q "@ build-failed .* cached" || fail "trace doesn't say cached (2)"
+echo "$log" | grep -q "@ build-succeeded .*-succeed" || fail "didn't keep going"