Move the runfiles for external repositories to under the x.runfiles/ directory

This also sets the Bazel workspace name to io_bazel_source.

Fixes #848.

Relevant to #1116, #1124,

RELNOTES[INC]: All repositories are now directly under the x.runfiles directory in the runfiles tree (previously, external repositories were at x.runfiles/main-repo/external/other-repo. This simplifies handling remote repository runfiles considerably, but will break existing references to external repository runfiles.
---
Furthermore, if a Bazel project does not provide a workspace name in the WORKSPACE file, Bazel will now default to using __main__ as the workspace name (instead of "", as previously). The repository's runfiles will appear under x.runfiles/__main__/.

--
MOS_MIGRATED_REVID=120224534

1 files changed, 3 insertions, 3 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/rules/python/PyCommon.java b/src/main/java/com/google/devtools/build/lib/rules/python/PyCommon.java
index c375701f14..50aebce23b 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/python/PyCommon.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/python/PyCommon.java
@@ -405,8 +405,8 @@ public final class PyCommon {
         } else {
           ruleContext.attributeError("srcs",
               buildMultipleMainMatchesErrorText(explicitMain, mainSourceName,
-                  mainArtifact.getRootRelativePath().toString(),
-                  outItem.getRootRelativePath().toString()));
+                  mainArtifact.getRunfilesPath().toString(),
+                  outItem.getRunfilesPath().toString()));
         }
       }
     }
@@ -417,7 +417,7 @@ public final class PyCommon {
     }
 
     PathFragment workspaceName = new PathFragment(ruleContext.getRule().getWorkspaceName());
-    return workspaceName.getRelative(mainArtifact.getRootRelativePath()).getPathString();
+    return workspaceName.getRelative(mainArtifact.getRunfilesPath()).getPathString();
   }
 
   public Artifact getExecutable() {