fix backtrace printed when cannot get lock.
change lock error handling code so exceptions have useful info and
exception handling in one place.
add test case for when cannot get lock.
changeset: 0:0acdaf898367
tag: tip
user: test
date: Mon Jan 12 13:46:40 1970 +0000
summary: test
b789fdd96dc2f3bd229c1dd8eedf0fc60e2b68e3 644 a
a
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1 files, 1 changesets, 1 total revisions