# `derivepassphrase` bug concurrency-testing-in-test-suite
???+ bug "Bug details: Test for concurrency and assert thread-safety in `derivepassphrase`'s test suite"
<table id="bug-summary" markdown>
<tr><th scope=col>Class<td><i>bug</i><td>This is clearly an actual problem we want fixed.
<tr><th scope=col>Priority<td><i>high</i><td>This should be fixed in the next release.
<tr><th scope=col>Difficulty<td><i>tricky</i><td>Needs many tuits.
<tr><th scope=col>Present-in<td colspan=2>0.1.0 0.1.1 0.1.2 0.2.0 0.3.0 0.3.1 0.3.2 0.3.3 <b>0.4.0</b>
<tr><th scope=col>Depends<td colspan=2>[concurrency-audit](concurrency-audit.md){: .fixed }
</table>
Once [concurrency-audit](concurrency-audit.md) is resolved, the thread-safety of `derivepassphrase` should be explicitly asserted in the test suite.
**Therefore**, assert the thread-safety of `derivepassphrase` in the test suite.
