CFLAGS=-Werror problems (was: rev 12354)

[Christian Stimming]

The C snippets in the ./configure file unfortunatly almost always fail 
miserably if your environment's CFLAGS contain -Werror. Somehow all 
those autoconf macro writers only tested for compiler errors, not for 
warning.

That is the actual reason for the --with-error-on-warning configure 
flag: That flag will *not* add -Werror at the *beginning* of ./configure 
but instead at the very *end* of ./configure, after all configure test 
programs have been compiled without that flag.

I would recommend removing -Werror from any of your default CFLAGS 
because as I said it will break almost any ./configure script in any 
existing project.

Christian

Mark Johnson schrieb:
> OOPS, must have hit reply instead of Reply All.
> 
> I believe that that is my CFLAGS in the configure 27271:  gcc -g ...  line.
> 
> It was the -Wunused -Werror that caused the problem.  One warns about 
> the unused variable (p in the test for fdopen).  The other makes 
> warnings into errors.
> Mark
> 
>>Mark Johnson <mrj001 at shaw.ca> writes:
>>
>>>>Can you cut-and-paste the portions of config.log about this test?
>>>>
>>>I found the following three lines in config.log, and that solved it for me:
>>>configure:27271: gcc -c -g -march=i486 -mcpu=pentium2 -g -Wall -Wunused 
>>>-Werror -D__USE_POSIX  conftest.c >&5
>>>conftest.c: In function `main':
>>>conftest.c:99: warning: unused variable `p'
>>>
>>>The CFLAGS I passed interacted with the unused variable p and fooled 
>>>configure into thinking there was no fdopen.  I changed my CFLAGS and 
>>>configure ran successfully.
>>>
>>>Mark