fix(3p/nix/tests): Fail DummyStore::addToStore on non-existent srcPath r/1389

Unfortunately, to guarantee correct behaviour of some evaluation (!)
tests, addToStore needs to actually check whether passed in source
files exist and fail appropriately.

There is a chance that the dependency on this behaviour is actually a
bug in the upstream test suite, but my attempts at finding out more
about this from, say, the git history have so far been unsuccessful.

Change-Id: I311999ea28fcedf5da13a4e627b1c1c8e4e59cbd
Reviewed-on: https://cl.tvl.fyi/c/depot/+/1276
Reviewed-by: isomer <isomer@tvl.fyi>
Reviewed-by: glittershark <grfn@gws.fyi>
Tested-by: BuildkiteCI

1 files changed, 2 insertions, 2 deletions

diff --git a/third_party/nix/src/tests/value-to-json.cc b/third_party/nix/src/tests/value-to-json.cc
index 19591b6fa1..fddeae512b 100644
--- a/third_party/nix/src/tests/value-to-json.cc
+++ b/third_party/nix/src/tests/value-to-json.cc
@@ -116,7 +116,7 @@ TEST_F(JSONValueTest, Path) {
   Value v;
   PathSet ps;
 
-  mkPath(v, "test");
+  mkPathNoCopy(v, "/exists-for-tests");
   printValueAsJSON(s, true, v, ss, ps);
   ASSERT_EQ(ss.str(), "\"/nix/store/g1w7hy3qg1w7hy3qg1w7hy3qg1w7hy3q-x\"");
 }
@@ -128,7 +128,7 @@ TEST_F(JSONValueTest, PathNoCopy) {
   Value v;
   PathSet ps;
 
-  mkPathNoCopy(v, "test");
+  mkPathNoCopy(v, "/exists-for-tests");
   printValueAsJSON(s, true, v, ss, ps);
   ASSERT_EQ(ss.str(), "\"/nix/store/g1w7hy3qg1w7hy3qg1w7hy3qg1w7hy3q-x\"");
 }