When using the TESTDATA feature from qmake, and including a file with a hash mark in it, it will include the hash mark in the generated makefile, which then comments out the rest of the line and any consecutive lines ending with a backslash (keeping the syntax correct ). The build will then fail because it is unable to locate the file (e.g. for file named "abc#123" it will complain it cannot find file "abc").

The same is also true for "qmake -project", which would require escaping as $${LITERAL_HASH}.