Failing back to --expunge when using --expunge_async on non-Linux machine

--expunge_async rely on setsid to create a new process group, this is
non-existent on Darwin nor on Windows. This lead to moving the output base
to a location and forget about it silently. Instead, we fall-back to
expunge_async until we completely fixes #1906.

--
Change-Id: Ia932613f687149a85f766de9faa7ce49aaa20b38
Reviewed-on: https://bazel-review.googlesource.com/6694
MOS_MIGRATED_REVID=136340995

1 files changed, 11 insertions, 1 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/runtime/commands/CleanCommand.java b/src/main/java/com/google/devtools/build/lib/runtime/commands/CleanCommand.java
index 923f89473e..3b1c68fae7 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/commands/CleanCommand.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/commands/CleanCommand.java
@@ -26,6 +26,7 @@ import com.google.devtools.build.lib.runtime.CommandEnvironment;
 import com.google.devtools.build.lib.shell.CommandException;
 import com.google.devtools.build.lib.util.CommandBuilder;
 import com.google.devtools.build.lib.util.ExitCode;
+import com.google.devtools.build.lib.util.OS;
 import com.google.devtools.build.lib.util.ProcessUtils;
 import com.google.devtools.build.lib.util.ShellEscaper;
 import com.google.devtools.build.lib.vfs.FileSystemUtils;
@@ -34,7 +35,6 @@ import com.google.devtools.common.options.Option;
 import com.google.devtools.common.options.OptionsBase;
 import com.google.devtools.common.options.OptionsParser;
 import com.google.devtools.common.options.OptionsProvider;
-
 import java.io.IOException;
 import java.util.logging.Logger;
 
@@ -98,6 +98,16 @@ public final class CleanCommand implements BlazeCommand {
       return ExitCode.COMMAND_LINE_ERROR;
     }
 
+    // TODO(dmarting): Deactivate expunge_async on non-Linux platform until we completely fix it
+    // for non-Linux platforms (https://github.com/bazelbuild/bazel/issues/1906).
+    if (cleanOptions.expunge_async && OS.getCurrent() != OS.LINUX) {
+      env.getReporter().handle(Event.info(null /*location*/,
+          "--expunge_async cannot be used on non-Linux platforms, falling back to --expunge"));
+      cleanOptions.expunge_async = false;
+      cleanOptions.expunge = true;
+      cleanOptions.cleanStyle = "expunge";
+    }
+
     String cleanBanner = cleanOptions.expunge_async ?
         "Starting clean." :
         "Starting clean (this may take a while). " +