$ alias spack
alias spack='spack -e otp-dev-mac'
$ spack find
==> In environment otp-dev-mac
==> Root specs
environment-modules  maven  osmctools  postgresql  py-mysql-connector  py-setuptools  python

==> 16 installed packages
-- darwin-highsierra-x86_64 / clang@9.0.0-apple -----------------
bzip2@1.0.6                 jdk@1.8.0_191  openssl@1.0.1h   py-mysql-connector@8.0.13  readline@7.0   zlib@1.2.11
environment-modules@3.2.10  maven@3.5.0    osmctools@0.9    py-setuptools@40.4.3       sqlite@3.26.0
gdbm@1.18.1                 ncurses@6.1    postgresql@10.3  python@3.6.5               tcl@8.6.8
$ spack uninstall python
==> Will not uninstall python@3.6.5%clang@9.0.0-apple/osojvpu
The following packages depend on it:
    -- darwin-highsierra-x86_64 / clang@9.0.0-apple -----------------
    qkjr5wm py-mysql-connector@8.0.13%clang
    vuarrj6 py-setuptools@40.4.3%clang

==> Error: There are still dependents.
  use `spack uninstall --dependents` to remove dependents too
$ spack uninstall --dependents python
==> The following packages will be uninstalled:

    -- darwin-highsierra-x86_64 / clang@9.0.0-apple -----------------
    qkjr5wm py-mysql-connector@8.0.13%clang
    vuarrj6 py-setuptools@40.4.3%clang
    osojvpu python@3.6.5%clang+dbm~optimizations patches=123082ab3483ded78e86d7c809e98a804b3465b4683c96bd79a2fd799f572244 +pic+pythoncmd~shared~tk~ucs4
==> Do you want to proceed? [y/N] y
==> Error: 'vuarrj6tr5yxov5cercjbre6fsxfauck'
$ \spack uninstall --dependents python
==> Will not uninstall python@3.6.5%clang@9.0.0-apple/osojvpu
The following packages depend on it:
    -- darwin-highsierra-x86_64 / clang@9.0.0-apple -----------------
    qkjr5wm py-mysql-connector@8.0.13%clang
    vuarrj6 py-setuptools@40.4.3%clang
    yufk7lh py-wheel@0.29.0%clang
It is used by the following environments:
    otp-dev-mac

==> Error: There are still dependents.
  use `spack uninstall --dependents` to remove dependents too
  use `spack env remove` to remove from environments