[MacPorts] #31056: Locking somewhat broken in MacPorts 2

[MacPorts]

#31056: Locking somewhat broken in MacPorts 2
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  Reporter:  ryandesign  |      Owner:  macports-tickets@…
      Type:  defect      |     Status:  new
  Priority:  Normal      |  Milestone:
 Component:  base        |    Version:  2.0.1
Resolution:              |   Keywords:
      Port:              |
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Comment (by ryandesign):

 Here is another instance of locking not working right, this one from
 MacPorts 2.4.2 on Mountain Lion. In one window I start to upgrade gnutls.
 While it is building, in another window, I upgrade libsoup which depends
 on glib-networking which depends on gnutls. It says it's waiting for a
 lock on gnutls, but once the first window finishes building gnutls and
 releases its lock and the second window gets it, it fails, while in the
 first window the upgrade of gnutls has successfully completed. Retrying
 the second window's upgrade of libsoup works.

 {{{
 $ sudo port -u upgrade libsoup
 Waiting for lock on
 /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_devel_gnutls/gnutls
 /work/.macports.gnutls.state
 --->  Computing dependencies for gnutls
 Waiting for lock on
 /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_devel_gnutls/gnutls
 /work/.macports.gnutls.state
 --->  Installing gnutls @3.5.16_0+universal
 Error: Failed to install gnutls: sqlite error: columns name, epoch,
 version, revision, variants are not unique (19) while executing query:
 INSERT INTO r
 egistry.ports (name, version, revision, variants, epoch) VALUES (?, ?, ?,
 ?, ?)
 Error: See
 /opt/local/var/macports/logs/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_devel_gnutls/gnutls/main.log
 for details.
 Error: Follow https://guide.macports.org/#project.tickets to report a bug.
 }}}

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Ticket URL: <https://trac.macports.org/ticket/31056#comment:1>
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