when building against OpenSSL, require at least version 1.1.1

[arvidn]

No description provided.

[xavier2k6]

Boost 1.85.0 is minimum available version on 2022 image, while 1.89.0 is currently maximum.

https://www.appveyor.com/docs/windows-images-software/#boost

[xavier2k6]

@arvidn specifying the OpenSSL version via find_package was introduced in CMake 3.20, correct?! so would that mean that you'd also have to bump cmake_minimum_required in code?

• https://github.com/search?q=repo%3Aarvidn%2Flibtorrent%20cmake_minimum_required&type=code
• https://cmake.org/cmake/help/latest/module/FindOpenSSL.html

[arvidn]

I see. and the appveyor image only has cmake 3.16.2. I may have to bump the image after all

[xavier2k6]

@arvidn How come you don't use something like set(minOpenSSLVersion 1.1.1) in CMakeLists.txt?

Below could be discarded then couldn't it?

#if OPENSSL_VERSION_NUMBER < 0x1010100fL
#error OpenSSL too old, libtorrent requires least OpenSSL 1.1.1 or later

I got a bit further with AppVeyor config & OpenSSL 3
https://ci.appveyor.com/project/arvidn/libtorrent/builds/53357292

[xavier2k6]

3x Python38 left to be changed....

[xavier2k6]

@arvidn might be no harm to resolve below "TODO's" & bump CMake to 3.21.0, add note in changelog.

libtorrent/CMakeLists.txt

Line 661 in 4479071

# TODO: migrate to CheckSourceCompiles in CMake >= 3.19

libtorrent/CMakeLists.txt

Line 736 in 4479071

# TODO: needed until https://gitlab.kitware.com/cmake/cmake/issues/19263 is fixed

[arvidn]

@xavier2k6 I think that's big enough change to warrant a second PR