In reply to @k900:0upti.me
https://github.com/NixOS/nixpkgs/pull/450577

I tried building that with jemalloc on pyside6 and got this:

-- Found WrapAtomic: TRUE
CMake Warning at /nix/store/zb7axlmjysv7dd5f67ljjs38nsikd8va-qtbase-6.10.0/lib/cmake/Qt6/Qt6Config.cmake:233 (find_package):
  Found package configuration file:

    /nix/store/zb7axlmjysv7dd5f67ljjs38nsikd8va-qtbase-6.10.0/lib/cmake/Qt6Core/Qt6CoreConfig.cmake

  but it set Qt6Core_FOUND to FALSE so package "Qt6Core" is considered to be
  NOT FOUND.  Reason given by package:

  Qt6Core could not be found because dependency JeMalloc could not be found.

  Configuring with --debug-find-pkg=JeMalloc might reveal details why the
  package was not found.

  Configuring with -DQT_DEBUG_FIND_PACKAGE=ON will print the values of some
  of the path variables that find_package uses to try and find the package.

Call Stack (most recent call first):
  CMakeLists.txt:18 (find_package)


CMake Error at CMakeLists.txt:18 (find_package):
  Found package configuration file:

    /nix/store/zb7axlmjysv7dd5f67ljjs38nsikd8va-qtbase-6.10.0/lib/cmake/Qt6/Qt6Config.cmake

  but it set Qt6_FOUND to FALSE so package "Qt6" is considered to be NOT
  FOUND.  Reason given by package:

  Failed to find required Qt component "Core".

  Expected Config file at
  "/nix/store/zb7axlmjysv7dd5f67ljjs38nsikd8va-qtbase-6.10.0/lib/cmake/Qt6Core/Qt6CoreConfig.cmake"
  exists



  Configuring with --debug-find-pkg=Qt6Core might reveal details why the
  package was not found.

  Configuring with -DQT_DEBUG_FIND_PACKAGE=ON will print the values of some
  of the path variables that find_package uses to try and find the package.



-- Configuring incomplete, errors occurred!