Shared memory error when profiling is enabled

[notmgsk]

Fixing the profiler (see quilc) results in an error:

# snip

TEST-DENSITY-QVM-NOISY-MEASURE-ALL                                      [ OK ]
[Test output: aaaaaaaaa]
  TEST-QVM-GARBAGE-COLLECTION                                             [ OK ]
[Test output: awdawdawdawdawdawdawdawdawdawdawdawdawdawdawdawd]
  TEST-POSIX-SHARED-MEMORY-ALLOCATION/DEALLOCATION                        [ OK ]
[Test output: awdawdawdawdawdawdawdawdawdawdawdawdawdawdawdawd]
  TEST-SHARED-ARRAY-ALLOCATION/DEALLOCATION                               [ OK ]
[Test output: aaaaaaaWhile evaluating the form starting at line 36, column 0
  of #P"/Users/mark.skilbeck/hackery/qvm/coverage-report/coverage-report.lisp":

debugger invoked on a SIMPLE-ERROR in thread
#<THREAD "main thread" RUNNING {10005C05B3}>:
  Error in shm_open. Got return code -1: File exists

Type HELP for debugger help, or (SB-EXT:EXIT) to exit from SBCL.

restarts (invokable by number or by possibly-abbreviated name):
  0: [CONTINUE                             ] Skip the rest of the test
                                             TEST-SHARED-QVM-GARBAGE-COLLECTION
                                             and continue by returning (values)
  1: [RETEST                               ] Rerun the test
                                             TEST-SHARED-QVM-GARBAGE-COLLECTION
  2:                                         Skip the rest of the test
                                             FIASCO-SUITES::QVM-TESTS and
                                             continue by returning (values)
  3:                                         Rerun the test
                                             FIASCO-SUITES::QVM-TESTS
  4: [CONTINUE-WITHOUT-DEBUGGING           ] Turn off debugging for this test
                                             session and invoke the first
                                             CONTINUE restart
  5: [CONTINUE-WITHOUT-DEBUGGING-ERRORS    ] Do not stop at unexpected errors
                                             for the rest of this test session
                                             and continue by invoking the first
                                             CONTINUE restart
  6: [CONTINUE-WITHOUT-DEBUGGING-ASSERTIONS] Do not stop at failed assertions
                                             for the rest of this test session
                                             and continue by invoking the first
                                             CONTINUE restart
  7: [ABORT-TESTING                        ] Abort the entire test session
  8: [RETRY                                ] Retry
                                             #<TEST-OP > on #<SYSTEM "qvm-tests">.
  9: [ACCEPT                               ] Continue, treating
                                             #<TEST-OP > on #<SYSTEM "qvm-tests">
                                             as having been successful.
 10:                                         Retry ASDF operation.
 11: [CLEAR-CONFIGURATION-AND-RETRY        ] Retry ASDF operation after
                                             resetting the configuration.
 12:                                         Retry ASDF operation.
 13:                                         Retry ASDF operation after
                                             resetting the configuration.
 14: [RETRY                                ] Retry EVAL of current toplevel form.
 15:                                         Ignore error and continue loading file "/Users/mark.skilbeck/hackery/qvm/coverage-report/coverage-report.lisp".
 16: [ABORT                                ] Abort loading file "/Users/mark.skilbeck/hackery/qvm/coverage-report/coverage-report.lisp".
 17:                                         Ignore runtime option --load "coverage-report.lisp".
 18:                                         Skip rest of --eval and --load options.
 19:                                         Skip to toplevel READ/EVAL/PRINT loop.
 20: [EXIT                                 ] Exit SBCL (calling #'EXIT, killing the process).

(QVM::MAKE-POSIX-SHARED-MEMORY "TEST_C__7" 1073741840)
   source: (ERROR "Error in shm_open. Got return code ~D: ~A" FD
                  (%STRERROR %ERRNO))
0]

It only happens when profiling is enabled.