De-duplicate the local-repo mountpoint in bootstrap

The code that is being dropped is duplicated in package_manager.py.

Complements: d4c1269
Relates: #381
Relates: #357
Relates: #1414
Relates: #1286

mock/py/mockbuild/util.py

@@ -33,8 +33,6 @@
 
 import distro
 
-from mockbuild.mounts import BindMountPoint
-
 from . import exception
 from . import file_util
 from . import text
@@ -1001,17 +999,6 @@ def _fix_cfg(cfg):
 
     _fix_cfg(bootstrap.config)
 
-    if not baseurl.startswith("file:///") and not baseurl.startswith("/"):
-        return
-
-    local_dir = baseurl.replace("file://", "", 1)
-    if not local_dir or not os.path.isdir(local_dir):
-        return
-
-    mountpoint = bootstrap.make_chroot_path(local_dir)
-    bootstrap.mounts.add(BindMountPoint(srcpath=local_dir,
-                                        bindpath=mountpoint))
-
 
 def subscription_redhat_init(opts, uidManager):
     if not opts['redhat_subscription_required']:

releng/release-notes-next/buildroot-mounts-redundancy.bugfix

@@ -0,0 +1,5 @@
+De-duplicating bootstrap mount points for local repositories used with `--chain`
+or `--localrepo=file:///repo/on/host`.  Caused eventual problems during
+`--scrub=bootstrap`.  This bug existed in Mock <= 5.6, but after fixing the
+[issue#1414][], it got exposed by our test suite.  Related issues include
+[issue#357][] ([commit#a0a2cba3][]) and [issue#381][] ([commit#16462acc][]).