Counter Strike: Source won’t start on NixOS

After the latest update of my NixOS machine, Counter Strike: Source wont start. Starting Steam from console shows the following error message

[...]
src/tcmalloc.cc:278] Attempt to free invalid pointer 0x94d1af0 
/home/user/.local/share/Steam/steamapps/common/Counter-Strike Source/hl2.sh: line 73: 14550 Aborted                 (core dumped) ${GAME_DEBUGGER} "${GAMEROOT}"/${GAMEEXE} "$@

I could fixed the problem by

• copy the libmimalloc.so from Half-Life 2 bin-folder (/home/user/.local/share/Steam/steamapps/common/Half-Life 2/bin/libmimalloc.so) to Conter-Strike: Source bin-folder
• Rename existing libtcmalloc_minimal.so.4 to libtcmalloc_minimal.so.4~ or similar
• rename libmimalloc.so to ibtcmalloc_minimal.so.4

The game now starts 🙂