Activating/deactivating Spack environments is incredibly slow:

$ time spack env activate .

real	2m13.037s
user	1m25.584s
sys	0m43.654s
$ time spack env deactivate

real	2m30.974s
user	1m38.090s
sys	0m49.781s

For comparison, for a similarly sized Conda environment:

$ time conda activate azureml_py38

real	0m0.099s
user	0m0.081s
sys	0m0.018s

Unfortunately, pyinstrument doesn't work for bash functions (which are required for env support), and spack --profile doesn't work either.

May be related to #25541, #25306