[FFmpeg-devel] [PATCH] configure: add check for pkg-config return value

[Diego Elio Pettenò]

Il giorno lun, 28/02/2011 alle 13.16 +0000, M?ns Rullg?rd ha scritto:
> 
> Could it have anything to do with the --as-needed flag?
> 
> 

Likely. OpenCV seems to list -lcvaux in its pkg-config line; if no
--as-needed is used, this library is always kept, and is always used to
satisfy the dependency on the RTMP_* symbols (indirectly).

When using --as-needed, there are no symbols defined in libcvaux that
would be used, so ld discards it, and you have the RTMP_* symbols
undefined.

Please note that Stefano's setup (without libssl-dev or equivalent)
would be considered broken by a distribution's point of view; on the
other hand that makes it all the more important to reject the
configuration sooner.

He's also probably using a pretty old ld, since modern versions should
have a "softer" --as-needed[1] that should make it not fail the link
(but you wouldn't like the results: it would depend on libcvaux and not
librtmp...).

[1] http://blog.flameeyes.eu/2009/02/07/a-softer-as-needed

-- 
Diego Elio Petten? ? Flameeyes
http://blog.flameeyes.eu/