libbtc: Where are the binaries generated?
How the console tells, maybe this is not the correct place, also because you receive a segmentation fault (core dumped) during the make check.

See ./test-suite.log
Please report to https://github.com/jonasschnelli/libbtc/issues

However, may you have installed the library in your system with the command sudo make install, this command puts the binaries of the library is a place where are all the libraries of the system?
Maybe you have only a failure in the check
But the last commit of this library is on Nov 4, 2018, and maybe this can be a signal of the motivation of your error.
I hope I clarify your idea