Debug failures on omnibus compilations

Author: nobu

tool/file2lastrev.rb

@@ -99,6 +99,7 @@ def self.format=(format)
     @output.write(data, overwrite: true, create_only: create_only)
   rescue => e
     next if @suppress_not_found and VCS::NotFoundError === e
+    raise
     warn "#{File.basename(Program)}: #{e.message}"
     ok = false
   end

tool/lib/vcs.rb

@@ -53,7 +53,9 @@ def popen(*args)
 module DebugSystem
   def system(*args, exception: true, **opts)
     VCS.dump(args, "args: ") if $DEBUG
-    super(*args, exception: exception, **opts)
+    ret = super(*args)
+    raise "Command failed with status (#$?): #{args.inspect}" if exception and !ret
+    ret
   end
 end