This adds an explicit unmount of the store volume to avoid cases
where the installer can hang in await_volume when:
- the user already has a store volume
- that volume is already mounted somewhere other than /nix
- they do not take a path through the installer that results in an
explicit unmount (as both removing and encrypting the volume
would do)
As reported in #5198, volume creation can fail with a permission error
for some macOS users (probably secondary user accounts?) Sudo appears
to be sufficient to avoid this.
While I'm here, I also updated the sudo invocation added in 079bde2ae
to use the _sudo explanation wrapper.
As mentioned in previous commit, Big Sur changes the syntax for the
xpath command slightly.
In the process of testing out replacements for these, I noticed a few
small simplification wins.
This should handle installation scenarios we can handle with
anything resembling confidence. Goal is approximating the existing
setup--not enforcing a best-practice...
Approaches (+ installer-handled, - manual) and configs each covers:
+ no change needed; /nix OK on boot volume:
All pre-Catalina (regardless of T2 or FileVault use)
+ create new unencrypted volume:
Catalina, pre-T2, no FileVault
+ create new encrypted-at-rest volume:
Catalina, pre-T2, FileVault
Catalina, T2, no FileVault
- require user to pre-create encrypted volume
Catalina, T2, FileVault
Starting macOS 10.15 /nix can't be creasted directly anymore due to the
readonly filesystem, but synthetic.conf was introduced to enable
creating mountpoints or symlinks for special usecases like package
managers.
