Inconsistent behavior for header-only library (INTERFACE)
When defining a header-only library I define an INTERFACE library. I then add some sources (headers) using target_sources with relative path Then I use target_include_directories with absolute path but when the library only target is target_linked to the header file cannot be found unless one uses full path in target_sources.
Discussion on this subject on the mailing: https://cmake.org/pipermail/cmake/2017-December/066704.html
Attached archive reproduce the issue.HeaderOnlyIssue.tgz