[Bug testsuite/70516] New: [4.9/5/6 Regression] Regtesting acts hangs on x86_64-apple-darwin15.4

["dominiq at lps dot ens.fr" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70516

            Bug ID: 70516
           Summary: [4.9/5/6 Regression] Regtesting acts hangs on
                    x86_64-apple-darwin15.4
           Product: gcc
           Version: 4.9.4
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: testsuite
          Assignee: unassigned at gcc dot gnu.org
          Reporter: dominiq at lps dot ens.fr
                CC: charlet at gcc dot gnu.org,
                    howarth.at.gcc.testresults at gmail dot com,
                    iains at gcc dot gnu.org
  Target Milestone: ---
              Host: x86_64-apple-darwin15.4
            Target: x86_64-apple-darwin15.4
             Build: x86_64-apple-darwin15.4

Starting after revision r234210 (OK) regtesting with acats never finish unless
I kill the most recent make. I see this behavior at r234234 (Mar 16). This
affects the number of acats tests that are run (see
https://gcc.gnu.org/ml/gcc-testresults/2016-04/msg00147.html and
https://gcc.gnu.org/ml/gcc-testresults/2016-04/msg00055.html). Note that after
killing the make I have also to kill several expect.

Tcl is 8.6.5, but using 8.5 does not help; dejagnu is 1.5.3.