Ignore broken git work directory at creating revision.h [ci skip]

tool/file2lastrev.rb

@@ -98,6 +98,7 @@ ok = true
     data.sub!(/(?<!\A|\n)\z/, "\n")
     @output.write(data, overwrite: true, create_only: create_only)
   rescue => e
+    next if @suppress_not_found and VCS::NotFoundError === e
     warn "#{File.basename(Program)}: #{e.message}"
     ok = false
   end

tool/lib/vcs.rb

@@ -479,7 +479,7 @@ class VCS
         last = cmd_read_at(srcdir, [[*gitcmd, 'rev-parse', ref, err: w]]).rstrip
         w.close
         unless r.eof?
-          raise "#{COMMAND} rev-parse failed\n#{r.read.gsub(/^(?=\s*\S)/, '  ')}"
+          raise VCS::NotFoundError, "#{COMMAND} rev-parse failed\n#{r.read.gsub(/^(?=\s*\S)/, '  ')}"
         end
       end
       log = cmd_read_at(srcdir, [[*gitcmd, 'log', '-n1', '--date=iso', '--pretty=fuller', *path]])