[MacPorts] #56577: Broken gcc7 port?

[MacPorts]

#56577: Broken gcc7 port?
------------------------------+--------------------
 Reporter:  thiagoveloso      |      Owner:  (none)
     Type:  defect            |     Status:  new
 Priority:  High              |  Milestone:
Component:  ports             |    Version:  2.5.0
 Keywords:  gcc7 broken port  |       Port:  gcc7
------------------------------+--------------------
 My Macbook Pro's system was pretty outdated and have been through quite a
 few updates recently - Macports 5.0, Xcode 9.4 and its Command Line Tools
 and finally macOS 10.13.5. Therefore, I am not exactly sure what caused
 the error below.

 I am trying to install gcc7, which finishes fine but throws an error
 message by the end of the installation that says something like: "Broken
 port and needs to be rebuild".

 Then, when running "port -d rev-upgrade", I get: "gcc7 is using libstdc++
 (this installation is configured to use libc++)". Then it tries to rebuild
 the port for another three times and finishes with a message: "still
 unable to build port after three attempts".

 I tried to ignore the message and go on installing my ports, but I always
 get the "broken port" message by the end of each installation.

 Is message something that I need to worry about? How can I fix it?

-- 
Ticket URL: <https://trac.macports.org/ticket/56577>
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