[FR] Allow linking against external mbedtsl

[werdahias]

Hi,

I started packaging this library for debian as prerequisite for openrgb. I encountered a few issues stemming from the embedding dependencies. No package in debian should depend/ship external libraries.

• json.hpp : Could you maybe add a check to find the system version first, then defaulting to the included copy ?
• mbed-tls: same issue basically. Otherwise I get the following warnings during the build:

dpkg-shlibdeps: warning: symbol mbedtls_ctr_drbg_random used by debian/libhueplusplus-dev/usr/lib/libhueplusplusshared.so found in none of the libraries
dpkg-shlibdeps: warning: symbol mbedtls_entropy_func used by debian/libhueplusplus-dev/usr/lib/libhueplusplusshared.so found in none of the libraries
dpkg-shlibdeps: warning: symbol mbedtls_timing_set_delay used by debian/libhueplusplus-dev/usr/lib/libhueplusplusshared.so found in none of the libraries
dpkg-shlibdeps: warning: symbol mbedtls_timing_get_delay used by debian/libhueplusplus-dev/usr/lib/libhueplusplusshared.so found in none of the libraries
dpkg-shlibdeps: warning: symbol mbedtls_x509_crt_init used by debian/libhueplusplus-dev/usr/lib/libhueplusplusshared.so found in none of the libraries
dpkg-shlibdeps: warning: symbol mbedtls_entropy_free used by debian/libhueplusplus-dev/usr/lib/libhueplusplusshared.so found in none of the libraries
dpkg-shlibdeps: warning: symbol mbedtls_ctr_drbg_init used by debian/libhueplusplus-dev/usr/lib/libhueplusplusshared.so found in none of the libraries
dpkg-shlibdeps: warning: symbol mbedtls_entropy_init used by debian/libhueplusplus-dev/usr/lib/libhueplusplusshared.so found in none of the libraries
dpkg-shlibdeps: warning: symbol mbedtls_ctr_drbg_seed used by debian/libhueplusplus-dev/usr/lib/libhueplusplusshared.so found in none of the libraries
dpkg-shlibdeps: warning: symbol mbedtls_ctr_drbg_free used by debian/libhueplusplus-dev/usr/lib/libhueplusplusshared.so found in none of the libraries

because the mbdedtls library from debian isn't picked up (and linked).

The tests aren't buildable offline either. I'd appreciate if you could employ a similar check because gtest and gmock are both in debian.

[Jojo-1000]

Hi, I implemented find_package for external libraries on the external-deps branch.
Could you please test that it correctly links to the external dependencies? I only tested that it still works without installed libraries.

[werdahias]

awesome, thank you! Unfortunately the version of mbedtls in debian is to old so I can't test the build. Once that gets updated I'll report back.

[werdahias]

since mbedtls 3.x is available in debian I will test this soon