diff --git a/lib/wit/common.py b/lib/wit/common.py
index f5ccd9a..0c206be 100755
--- a/lib/wit/common.py
+++ b/lib/wit/common.py
@@ -18,7 +18,7 @@ def print_errors(errors):
 
     for err in errors:
         log.info("--- ERROR ---")
-        log.info(err)
+        log.info(str(err))
 
 
 class WitUserError(Exception):
diff --git a/lib/wit/main.py b/lib/wit/main.py
index 7724b44..93d4bd6 100644
--- a/lib/wit/main.py
+++ b/lib/wit/main.py
@@ -78,7 +78,9 @@ def main() -> None:
     update_dep_parser.add_argument('pkg', metavar='pkg[::revision]', type=parse_dependency_tag)
 
     subparsers.add_parser('status', help='show status of workspace')
-    subparsers.add_parser('update', help='update git repos')
+
+    update_parser = subparsers.add_parser('update', help='update git repos')
+    update_parser.add_argument('--force', action='store_true', help='checkout regardless of errors')
 
     inspect_parser = subparsers.add_parser('inspect', help='inspect lockfile')
     inspect_group = inspect_parser.add_mutually_exclusive_group()
@@ -358,10 +360,15 @@ def status(ws, args) -> None:
 
 def update(ws, args) -> None:
     packages, errors = ws.resolve(download=True)
-    if len(errors) == 0:
-        ws.checkout(packages)
-    else:
+
+    # the errors assume the repos are still in .wit
+    if len(errors) > 0:
         print_errors(errors)
+
+    if len(errors) == 0 or ('force' in args and args.force):
+        ws.checkout(packages)
+
+    if len(errors) > 0:
         sys.exit(1)
 
 
diff --git a/t/wit_ancestry_force.t b/t/wit_ancestry_force.t
new file mode 100755
index 0000000..fe41fe9
--- /dev/null
+++ b/t/wit_ancestry_force.t
@@ -0,0 +1,70 @@
+#!/usr/bin/env bash
+
+. $(dirname $0)/regress_util.sh
+
+prereq "on"
+
+make_repo 'xyz'
+
+cd xyz
+touch zero
+git add -A
+git commit -m "xyz:0"
+
+git checkout -b branch_a
+touch testa
+git add -A
+git commit -m "xyz:a"
+xyz_commit_a=$(git rev-parse HEAD)
+
+git checkout master
+
+git checkout -b branch_b
+touch testb
+git add -A
+git commit -m "xyz:b"
+xyz_commit_b=$(git rev-parse HEAD)
+cd ..
+
+make_repo 'foo'
+cat << EOF | jq . > foo/wit-manifest.json
+[
+    { "commit": "$xyz_commit_b", "name": "xyz", "source": "$PWD/xyz" }
+]
+EOF
+git -C foo add -A
+git -C foo commit -m "add xyz:2"
+foo_commit=$(git -C foo rev-parse HEAD)
+
+# Set up repo foo
+make_repo 'bar'
+cat << EOF | jq . > bar/wit-manifest.json
+[
+    { "commit": "$xyz_commit_a", "name": "xyz", "source": "$PWD/xyz" }
+]
+EOF
+git -C bar add -A
+git -C bar commit -m "add xyz:1"
+
+prereq "off"
+
+# Now create a workspace from main_repo
+wit init myws -a $PWD/foo -a $PWD/bar
+
+check "wit init should fail with AncestryError" [ $? -ne 0 ]
+
+cd myws
+wit update
+check "wit update should fail with AncestryError" [ $? -ne 0 ]
+
+ls foo || ls bar || ls xyz
+check "repos should not be checked out" [ $? -ne 0 ]
+
+wit update --force
+check "wit update --force should return non-zero exit code" [ $? -ne 0 ]
+
+ls foo && ls bar && ls xyz
+check "repos should be checked out" [ $? -eq 0 ]
+
+report
+finish