$ cat >> $HGRCPATH << EOF
  > [extensions]
  > fbamend=
  > inhibit=
  > smartlog=
  > [experimental]
  > evolution = createmarkers
  > EOF

Test that changesets with visible precursors are rendered as x's, even
with the inhibit extension enabled.
  $ hg init repo
  $ cd repo
  $ hg debugbuilddag +4
  $ hg book -r 3 test
  $ hg up 1
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg amend -m "amended" --no-rebase
  hint[amend-restack]: descendants of 66f7d451a68b are left behind - use 'hg restack' to rebase them
  hint[hint-ack]: use 'hg hint --ack amend-restack' to silence these hints
  $ hg smartlog -T '{rev} {bookmarks}'
  @  4
  |
  | o  3 test
  | |
  | o  2
  | |
  | x  1
  |/
  o  0
  
  $ hg unamend
  $ hg up 2
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg smartlog -T '{rev} {bookmarks}'
  o  3 test
  |
  @  2
  |
  ~