[MacPorts] #55200: gmp @6.1.2 configure: error: cannot find output from flex; giving up

[MacPorts]

#55200: gmp @6.1.2 configure: error: cannot find output from flex; giving up
------------------------------+---------------------------------
  Reporter:  stefan-c-kremer  |      Owner:  MarcusCalhoun-Lopez
      Type:  defect           |     Status:  assigned
  Priority:  Normal           |  Milestone:
 Component:  ports            |    Version:
Resolution:                   |   Keywords:
      Port:  gmp              |
------------------------------+---------------------------------

Comment (by stefan-c-kremer):

 When it tried to do that step manually:
 {{{
 Command failed:  cd
 "/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_devel_gmp/gmp/work/gmp-6.1.2"
 && ./configure --prefix=/opt/local --enable-cxx
 Exit code: 1
 }}}
 Typing:
 {{{
 cd
 "/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_devel_gmp/gmp/work/gmp-6.1.2"
 sudo ./configure --prefix=/opt/local --enable-cxx
 }}}
 it ends with:
 {{{
 config.status: linking mpn/x86_64/coreihwl/gmp-mparam.h to gmp-mparam.h
 config.status: executing libtool commands
 configure: summary of build options:

   Version:           GNU MP 6.1.2
   Host type:         haswell-apple-darwin17.0.0
   ABI:               64
   Install prefix:    /opt/local
   Compiler:          gcc
   Static libraries:  yes
   Shared libraries:  yes

 $ echo $?
 0

--
Ticket URL: <https://trac.macports.org/ticket/55200#comment:10>
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