pmbootstrap chroot: fix --image bugs (MR 2556)

- Properly run commands at host to mount rootfs
- Always refuse to zap chroot_image, since it is never added to workdir.cfg

Co-authored-by: Newbyte <newbyte@postmarketos.org>

pmb/chroot/mount.py

@@ -31,11 +31,12 @@ def mount_chroot_image(chroot: Chroot) -> None:
     )
     pmb.helpers.mount.bind_file(loopdev, chroot_native / "dev/install")
     # Set up device mapper bits
-    pmb.chroot.root(["kpartx", "-u", "/dev/install"], chroot_native)
+    pmb.helpers.run.root(["kpartx", "-u", loopdev])
     chroot.path.mkdir(exist_ok=True)
+    loopdev_basename = os.path.basename(loopdev)
     # # The name of the IMAGE chroot is the path to the rootfs image
-    pmb.helpers.run.root(["mount", "/dev/mapper/install2", chroot.path])
-    pmb.helpers.run.root(["mount", "/dev/mapper/install1", chroot.path / "boot"])
+    pmb.helpers.run.root(["mount", f"/dev/mapper/{loopdev_basename}p2", chroot.path])
+    pmb.helpers.run.root(["mount", f"/dev/mapper/{loopdev_basename}p1", chroot.path / "boot"])
 
     pmb.config.workdir.chroot_save_init(chroot)
 

pmb/config/workdir.py

@@ -12,7 +12,7 @@ from typing import overload
 
 import pmb.config
 import pmb.config.pmaports
-from pmb.core import Chroot
+from pmb.core import Chroot, ChrootType
 from pmb.core.context import get_context
 from pmb.helpers import logging
 
@@ -86,6 +86,9 @@ def chroot_check_channel(chroot: Chroot) -> bool:
     """Check the chroot channel against the current channel. Returns
     True if the chroot should be zapped (both that it needs zapping and
     the user has auto_zap_misconfigured_chroots enabled), False otherwise."""
+    if chroot.type == ChrootType.IMAGE:
+        return False
+
     config = get_context().config
     path = config.work / "workdir.cfg"
     msg_again = (