c_glib testbufferedtransport failed in a CI build

Intermittent test failure:

32: Test command: /thrift/src/thrift-1.0.0-dev/cmake_build/bin/testbufferedtransport
32: Test timeout computed to be: 1500
32: /testbufferedtransport/CreateAndDestroy: OK
32: /testbufferedtransport/OpenAndClose: OK
32: /testbufferedtransport/ReadAndWrite: OK
32: testbufferedtransport: ../lib/c_glib/test/testbufferedtransport.c:246: test_write_fail: Assertion `thrift_buffered_transport_open (transport, ((void *)0)) == (!(0))' failed.
32: /testbufferedtransport/WriteFail:
32/51 Test #32: testbufferedtransport ..............***Exception: Other 2.11 sec

Running this test in a loop would likely reproduce it.