LibreCAD_3 cmake hits undefined reference to `pthread

it seemed there are 3 instances of the same / similar problem

https://github.com/LibreCAD/LibreCAD_3/issues/192
http://forum.librecad.org/compile-failed-on-Debian-jessie-td5717401.html
http://forum.librecad.org/cmake-hits-undefined-reference-to-pthread-create-td5717442.html ^^ i encountered this last one and posted that in librecad-3 dev forum currently still unresolved

Jun 05 '19 20:06 ag88

i tried going into build and run cmake ../subdirectory apparently lcviewernoqt, lcUILua did not produce the pthread error for the other subdirectories, the error is produced but surprisingly a makefile is generated,

but if cmake .. is run, it would end with Configuring incomplete, errors occurred! See also "/home/user/src/LibreCAD_3/build/CMakeFiles/CMakeOutput.log". See also "/home/user/src/LibreCAD_3/build/CMakeFiles/CMakeError.log".

Jun 05 '19 20:06 ag88

i think this is a bug in cmake FindThreads module but so far have not found a fix for it

Jun 05 '19 21:06 ag88

cross link forum post: http://forum.librecad.org/cmake-hits-undefined-reference-to-pthread-create-td5717442.html

Jun 05 '19 22:06 lordofbikes

i logged the issue with cmake - kitware - the company itself https://gitlab.kitware.com/cmake/cmake/issues/19344

Jun 06 '19 09:06 ag88

cmake hits undefined reference to `pthread_create'