Hashmark (#) in file names are not escaped by qt creator (bug report)
There is no "issue" tab in the github project which I assume is https://github.com/qtproject/qt-creator
so I give a bug description in here.
When I add all files in a directory in a lib project in qt creator (by right clicking and selecting "Add Existing Directory") those filenames that will be added to the pro file will if they contains the character # not be escaped to $$(LITERAL_HASH). Build errors will therefor occur.
Search and replace will be needed to correct the pro file.
I can confirm the bug but you should report it at https://bugreports.qt.io not here.
Qt main repository is http://code.qt.io not github