texstudio @2.5.1: All compilers are either blacklisted or unavailable

[bringingheavendown (Honi Sanders)]

Command line output:

User$ sudo port install texstudio
Warning: All compilers are either blacklisted or unavailable; defaulting to first fallback option
Warning: All compilers are either blacklisted or unavailable; defaulting to first fallback option
Warning: All compilers are either blacklisted or unavailable; defaulting to first fallback option
Warning: All compilers are either blacklisted or unavailable; defaulting to first fallback option
Warning: All compilers are either blacklisted or unavailable; defaulting to first fallback option
Warning: All compilers are either blacklisted or unavailable; defaulting to first fallback option
Warning: All compilers are either blacklisted or unavailable; defaulting to first fallback option
--->  Computing dependencies for texstudio
--->  Fetching archive for texstudio
--->  Attempting to fetch texstudio-2.5.1_0.darwin_15.x86_64.tbz2 from https://packages.macports.org/texstudio
--->  Attempting to fetch texstudio-2.5.1_0.darwin_15.x86_64.tbz2 from http://mse.uk.packages.macports.org/sites/packages.macports.org/texstudio
--->  Attempting to fetch texstudio-2.5.1_0.darwin_15.x86_64.tbz2 from http://lil.fr.packages.macports.org/texstudio
--->  Fetching distfiles for texstudio
--->  Verifying checksums for texstudio
--->  Extracting texstudio
--->  Applying patches to texstudio
--->  Configuring texstudio
Warning: All compilers are either blacklisted or unavailable; defaulting to first fallback option
Warning: All compilers are either blacklisted or unavailable; defaulting to first fallback option
Warning: All compilers are either blacklisted or unavailable; defaulting to first fallback option
Warning: All compilers are either blacklisted or unavailable; defaulting to first fallback option
Warning: All compilers are either blacklisted or unavailable; defaulting to first fallback option
Warning: All compilers are either blacklisted or unavailable; defaulting to first fallback option
Warning: All compilers are either blacklisted or unavailable; defaulting to first fallback option
Warning: All compilers are either blacklisted or unavailable; defaulting to first fallback option
Warning: All compilers are either blacklisted or unavailable; defaulting to first fallback option
Warning: All compilers are either blacklisted or unavailable; defaulting to first fallback option
Warning: All compilers are either blacklisted or unavailable; defaulting to first fallback option
Warning: All compilers are either blacklisted or unavailable; defaulting to first fallback option
Warning: All compilers are either blacklisted or unavailable; defaulting to first fallback option
Warning: All compilers are either blacklisted or unavailable; defaulting to first fallback option
Warning: All compilers are either blacklisted or unavailable; defaulting to first fallback option
Warning: All compilers are either blacklisted or unavailable; defaulting to first fallback option
Warning: All compilers are either blacklisted or unavailable; defaulting to first fallback option
Warning: All compilers are either blacklisted or unavailable; defaulting to first fallback option
--->  Building texstudio
Error: org.macports.build for port texstudio returned: command execution failed
Please see the log file for port texstudio for details:
    /opt/local/var/macports/logs/_opt_local_var_macports_sources_rsync.macports.org_release_tarballs_ports_editors_texstudio/texstudio/main.log
To report a bug, follow the instructions in the guide: http://guide.macports.org/#project.tickets
Error: Processing of port texstudio failed

From /opt/local/var/macports/logs/_opt_local_var_macports_sources_rsync.macports.org_release_tarballs_ports_editors_texstudio/texstudio/main.log:

:info:build debughelper.cpp:606:19: error: use of undeclared identifier 'pthread_self'
:info:build                         mainThreadID = pthread_self();
:info:build                                        ^
:info:build 1 error generated.
:info:build make: *** [.obj/debughelper.o] Error 1

The "Warning: All compilers are either blacklisted or unavailable; defaulting to first fallback option" warning is strange because I definitely have clang installed. I don't know what to make of that.

[bringingheavendown (Honi Sanders)]

log file for port texstudio

[ryandesign (Ryan Carsten Schmidt)]

Duplicate of #47539.