Make the execution root match the runfiles tree structure for external repositories

One interesting side effect of how this is implemented is that for external
repositories, bin/ and genfiles/ are combined.  External repo output is under
bazel-out/local-fastbuild/repo_name for each repo.

Fixes #1262.

RELNOTES[INC]: Previously, an external repository would be symlinked into the
execution root at execroot/local_repo/external/remote_repo. This changes it to
be at execroot/remote_repo. This may break genrules/Skylark actions that
hardcode execution root paths. If this causes breakages for you, ensure that
genrules are using $(location :target) to access files and Skylark rules are
using http://bazel.io/docs/skylark/lib/File.html's path, dirname, etc.
functions.

--
MOS_MIGRATED_REVID=125095799

1 files changed, 1 insertions, 1 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/packages/Package.java b/src/main/java/com/google/devtools/build/lib/packages/Package.java
index 44d9e308a3..ae0915e3cd 100644
--- a/src/main/java/com/google/devtools/build/lib/packages/Package.java
+++ b/src/main/java/com/google/devtools/build/lib/packages/Package.java
@@ -294,7 +294,7 @@ public class Package {
     this.filename = builder.getFilename();
     this.packageDirectory = filename.getParentDirectory();
 
-    this.sourceRoot = getSourceRoot(filename, packageIdentifier.getPathFragment());
+    this.sourceRoot = getSourceRoot(filename, packageIdentifier.getPackageFragment());
     if ((sourceRoot == null
         || !sourceRoot.getRelative(packageIdentifier.getPathFragment()).equals(packageDirectory))
         && !filename.getBaseName().equals("WORKSPACE")) {