[MacPorts] FAQ modified

[MacPorts Wiki]

Page "FAQ" was changed by JDLH
Diff URL: <https://trac.macports.org/wiki/FAQ?action=diff&version=194>
Revision 194
Comment: +section Why am I getting a message, "Warning… indications of -Wimplicit-function-declaration"?
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Index: FAQ
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--- FAQ (version: 193)
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 After playing whack-a-mole for a while trying to get stuff to coexist, MacPorts has given up and acknowledged that the only thing that works reliably is to go with what is compatible with Apple libraries; that means only older LLVM/`clang` that uses pre-C++11 interfaces (provided by `libstdc++` or an Apple-sourced compatible `libc++`) on 10.8 and earlier and only newer LLVM/`clang` that uses C++11 interfaces (provided by modern `libc++` but not the `libc++` shipped on older OS X) on 10.9 and later. Any other combination ''might'' work if you are lucky, but is not guaranteed in any way and has led to many port build failures, and MacPorts no longer attempts to support it.
 
+=== Why am I getting a message, "Warning… indications of -Wimplicit-function-declaration"? ===
+
+When you build a port, you may see a message like, "Warning: Configuration logfiles contain indications of -Wimplicit-function-declaration; check that features were not accidentally disabled" in the configuration log. 
+
+This is a warning for the upstream developers of the port's source code. Each occurrence must be investigated and handled individually. As the user of a port, we encourage you to file bug reports about each such message in each port where you observe it. [https://guide.macports.org/#project.tickets Filing a MacPorts ticket] against the port, including the specific message you see, is a helpful first step. This lets the other people who use and maintain the port track the problem. Diagnosing what the port's configuration code is trying to do is even more helpful.  Most helpful of all is to file a bug report against the upstream project which supplies the source code. That is where the problem needs to be fixed ultimately.  Then the fix will flow downstream to MacPorts. The problem will be solved. The message will no longer appear.
+
+See WimplicitFunctionDeclaration for more detailed information about this message, its causes, and what to do about it.
+
+ 
+
 == Portfile Development and Maintenance Questions ==
 
 === Is it possible to have a dependency on a specific variant of another port? E.g. "postgresql8 +server"? === #dependonvariant
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