[MacPorts] #59445: restore_ports.tcl script fails with the error "infinite loop" (deps cycle) (was: restore_ports.tcl script fails with the error "infinite loop" (deps bug))

[MacPorts]

#59445: restore_ports.tcl script fails with the error "infinite loop" (deps cycle)
---------------------+--------------------
  Reporter:  JDLH    |      Owner:  (none)
      Type:  defect  |     Status:  new
  Priority:  Normal  |  Milestone:
 Component:  base    |    Version:
Resolution:          |   Keywords:
      Port:          |
---------------------+--------------------

Old description:

> I recently updated my macOS version from 10.11 El Capitan to macOS High
> Sierra 10.13.6. I am following the
> [https://trac.macports.org/wiki/Migration Migration instructions].
>
> When I ran the `restore_ports.tcl` script, it failed with the error
> message:
>
> {{{
> Error: we appear to be stuck, exiting...
> infinite loop
>     while executing
> "sort_ports $portList"
>     invoked from within
> "set operationList [sort_ports $portList]"
>     (file "./restore_ports.tcl" line 285)
> }}}
>
> I did some investigation, adding diagnostic statements to
> `restore_ports.tcl` . My conclusion is that the underlying cause of the
> problem is an error in the script's gathering of dependencies for one
> port it was trying to restore, which so happened to cause a dependency
> cycle with another port it was also trying to restore. The cycle meant
> that it could not come up with an installation order for these two ports,
> and issued the "infinite loop" error message. Details below.
>
> My **workaround** was to edit my list of ports to restore. I looked at
> the ports involved in the cycle. One was clearly little used, I didn't
> even recognise it. I removed that from my list of ports. I also had
> hundreds of entries for old versions of ports which were no longer
> active; I removed all of them also. With this change, `restore_ports.tcl`
> was able to avoid the dependency cycle, and the restore is underway.
>
> This problem is similar to https://trac.macports.org/ticket/49210
> 'restore_ports.tcl script on fails on El Capitan with the error "infinite
> loop"'. That ticket did not come up with a clear solution to their
> problem, and it is closed and four years old. I think it's better to open
> a new ticket than to add this commentary on to that ticket. Hopefully
> others with this problem will find the workaround helpful, even before
> the underlying bug gets fixed.
>
> **Versions**: \\
> macOS High Sierra 10.13.6 \\
> Xcode 10.1 [but I think not involved in this bug] \\
> restore_ports.tcl: https://github.com/macports/macports-
> contrib/raw/master/restore_ports/restore_ports.tcl (I believe commit
> 75135bd from Mar 24, 2015). \\
> Port with incorrect dependency calculation: librsvg \\
> Port incorrectly listed as dependency, causing cycle: adwaita-icon-theme

New description:

 I recently updated my macOS version from 10.11 El Capitan to macOS High
 Sierra 10.13.6. I am following the
 [https://trac.macports.org/wiki/Migration Migration instructions].

 When I ran the `restore_ports.tcl` script, it failed with the error
 message:

 {{{
 Error: we appear to be stuck, exiting...
 infinite loop
     while executing
 "sort_ports $portList"
     invoked from within
 "set operationList [sort_ports $portList]"
     (file "./restore_ports.tcl" line 285)
 }}}

 I did some investigation, adding diagnostic statements to
 `restore_ports.tcl` . My conclusion is that the underlying cause of the
 problem is that: a) some of the ports in my list had a mutual dependency
 cycle, and b) the script could not come up with an installation order for
 these two ports. Thus it issued the "infinite loop" error message. Details
 below.

 My **workaround** was to edit my list of ports to restore. I looked at the
 ports involved in the cycle. One was clearly little used, I didn't even
 recognise it. I removed that from my list of ports. I also had hundreds of
 entries for old versions of ports which were no longer active; I removed
 all of them also. With this change, `restore_ports.tcl` was able to avoid
 the dependency cycle, and the restore is underway.

 This problem is similar to https://trac.macports.org/ticket/49210
 'restore_ports.tcl script on fails on El Capitan with the error "infinite
 loop"'. That ticket did not come up with a clear solution to their
 problem, and it is closed and four years old. I think it's better to open
 a new ticket than to add this commentary on to that ticket. Hopefully
 others with this problem will find the workaround helpful, even before the
 underlying bug gets fixed.

 **Versions**: \\
 macOS High Sierra 10.13.6 \\
 Xcode 10.1 [but I think not involved in this bug] \\
 restore_ports.tcl: https://github.com/macports/macports-
 contrib/raw/master/restore_ports/restore_ports.tcl (I believe commit
 75135bd from Mar 24, 2015). \\
 Port with incorrect dependency calculation: librsvg \\
 Port incorrectly listed as dependency, causing cycle: adwaita-icon-theme

--

Comment (by JDLH):

 Changed the title and the introduction of the ticket to withdraw my claim
 that the script gathers dependencies incorrectly. It appears to gather
 dependencies correctly. It appears unable, however, to deal with a
 dependency cycle. MacPorts itself appears to be able to handle the
 dependency cycle.

-- 
Ticket URL: <https://trac.macports.org/ticket/59445#comment:2>
MacPorts <https://www.macports.org/>
Ports system for macOS