gnudatalanguage @0.9.6: Could NOT find Threads (missing: Threads_FOUND)

[hstraoulduke8@…]

Using OS X El Capitan I'm trying to download gnudatalanguage for the first time on this computer. I've downloaded Xcode and command line tools. I get through most of the installation but get the following error when "Configuring gnudatalanguage". The main.log file error shows the following failures (full main.log file attached):

/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_release_tarballs_ports_math_gnudatalanguage/gnudatalanguage/work/gdl-0.9.6 
:info:configure Exit code: 1
:error:configure org.macports.configure for port gnudatalanguage returned: configure failure: command execution failed
:debug:configure Error code: NONE
:debug:configure Backtrace: configure failure: command execution failed
    while executing
"portconfigure::configure_main org.macports.configure"
    ("eval" body line 1)
    invoked from within
"eval $procedure $targetname"
:info:configure Warning: targets not executed for gnudatalanguage: org.macports.activate org.macports.configure org.macports.build org.macports.destroot org.macports.install

[larryv (Lawrence Velázquez)]

Please attach the actual main.log text file.

[ryandesign (Ryan Carsten Schmidt)]

And please ​clean and try again before doing so.

[hstraoulduke8@…]

Ticket can be closed. Clean and reinstall resolved the issue. Apologies for not doing so beforehand, and thanks for the assistance. For informational purposes in case it helps future tickets, macports was installed with version OS X Yosemite and it's possible I had tried to install gnudatalanguage with a previous version of macports. Perhaps the previous errors persisted until the clean process was run.