OpenSSL 4.0 is in experimental. This package fails to build against it:

| -- OPENSSL_VERSION (system) is ..
| --
| Not a supported openssl version in WITH_SSL=system.
| Make sure you have specified a supported SSL version.
| Valid options are :
| openssl[0-9]+ (use alternative system library)
| yes (synonym for system)
| </path/to/custom/openssl/installation>
|
| CMake Error at cmake/ssl.cmake:84 (MESSAGE):
|   Please install the appropriate openssl developer package.
|
| Call Stack (most recent call first):
|   cmake/ssl.cmake:406 (FATAL_SSL_NOT_FOUND_ERROR)
|   CMakeLists.txt:1862 (MYSQL_CHECK_SSL)
|
|
| -- Configuring incomplete, errors occurred!
| make[1]: *** [debian/rules:80: configure-stamp] Error 1

Full buildlog
https://breakpoint.cc/openssl-rebuild/logs-4/attempted/mysql-8.0_8.0.45-1_amd64-2026-04-19T14:09:47Z

Sebastian