[MacPorts] #50528: logwatch: does not properly delete old unregistered /opt/local/bin/logwatch symlink (was: logwatch: build fails on all buildbots during activation)

[MacPorts]

#50528: logwatch: does not properly delete old unregistered /opt/local/bin/logwatch
symlink
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  Reporter:  devans@…  |      Owner:  ryandesign@…
      Type:  defect    |     Status:  closed
  Priority:  Normal    |  Milestone:
 Component:  ports     |    Version:  2.3.4
Resolution:  fixed     |   Keywords:
      Port:  logwatch  |
-----------------------+--------------------------
Changes (by ryandesign@…):

 * cc: khindenburg@… (added)
 * status:  new => closed
 * component:  server/hosting => ports
 * resolution:   => fixed


Comment:

 No parts of the buildbot slave infrastructure are installed in /opt/local.
 /opt/local is under the control of the buildbot, for building MacPorts
 packages.

 The problem affects user systems as well, not just the buildbot machines.

 This is a bug in the logwatch portfile. It used to directly install the
 /opt/local/bin/logwatch symlink, bypassing the destroot. This was fixed in
 r127811 and r127812 to correctly install the symlink as part of the
 destroot, but for existing installations the old unregistered symlink
 remained, preventing upgrades from activating correctly, as you've seen.

 Attempts were made to fix this in r127815 and r127816 but the attempts
 were incorrect. The most recent attempted fix doesn't work as intended
 because it uses `file exists` to check for the file's existence, but `file
 exists` resolves symlinks, so it is actually checking if the file the
 symlink points to exists, which it doesn't, so it doesn't get deleted. The
 existence of the symlink itself needs to be tested.

 I fixed this for logwatch in r145392 the same way I had fixed it for nedi
 in r143403.

-- 
Ticket URL: <https://trac.macports.org/ticket/50528#comment:1>
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