Dear Maintainer, boost 1.90 has become the default in Debian unstable. This version of boost has seen the removal of the system library. stopt does not build anymore against boost 1.90 because of this, yet it is enough to stop looking for the "system" component in CMakeLists.txt: change `FIND_PACKAGE(Boost COMPONENTS unit_test_framework system timer chrono log thread REQUIRED)` to `FIND_PACKAGE(Boost COMPONENTS unit_test_framework timer chrono log thread REQUIRED)` and also remove "system" from all TARGET_LINK_LIBRARIES invocations. Best regards, Pierre