WIP: Support repository pinning

closes #1737 (closed)

I am having trouble with this code so far. I get the following error:

ERROR: 'postmarketos-base@pmos' is not a valid child dependency, format is name([<>~=]version)

However, if I run ./pmbootstrap chroot I can run sudo apk add postmarketos-base@pmos and apk pulls the correct dependencies:

(105/108) Installing libpsl (0.21.0-r1)
(106/108) Installing networkmanager (1.24.0-r0)
Executing networkmanager-1.24.0-r0.pre-install
  *
  * To setup system connections, regular users must be member of 'plugdev' group.
  *
  *
  * To control WiFi devices, enable wpa_supplicant service: 'rc-update add wpa_supplicant default'
  * then reboot the system or restart 'wpa_supplicant' and 'networkmanager' services respectively.
  *
(107/108) Installing networkmanager-openrc (1.24.0-r0)
(108/108) Installing postmarketos-base@pmos (3-r33)
Executing postmarketos-base-3-r33.post-install
- Modifying: /etc/fstab
- Modifying: /etc/issue
- Modifying: /etc/motd
- Modifying: /etc/conf.d/syslog
- Modifying: /etc/conf.d/wpa_supplicant
- Modifying: /etc/sudoers
- Modifying: /etc/chrony/chrony.conf (adding makestep)
- Modifying: /etc/chrony/chrony.conf (removing initstepslew)
Executing busybox-1.31.1-r15.trigger
Executing eudev-3.2.9-r3.trigger
Executing fontconfig-2.13.1-r2.trigger
Executing mkfontscale-1.2.1-r1.trigger
Executing postmarketos-mkinitfs-0.12.1-r0.trigger
Executing dbus-1.12.16-r4.trigger
Executing ca-certificates-20191127-r2.trigger
Executing postmarketos-base-3-r33.trigger
OK: 104 MiB in 149 packages

Any reason why chrooting works but my install function doesnt work?