[BuildTools] BuildTools version incompatibilities (cygwin, -mno-cygwin)

[Andreas Waechter]

Hi Lou,

> 	There have been a couple of tickets posted (Osi, CoinUtils, 
> BuildTools) complaining about a compile problem on cygwin (_isnan not 
> declared).  I can't duplicate this error (I suspect it's fixed in the 
> current BuildTools), but the current Osi stable (0.95) and point release 
> are incorporating externals with incompatible versions of coin.m4. 
> CoinUtils has upgraded to a version with the --enable-doscompile flag, 
> hence -mno-cygwin is absent by default.  But the clp and dylp point 
> releases are still built with an early BuildTools that does not have 
> --enable-doscompile and hence uses -mno-cygwin by default.

I didn't try to find out what the problem is, but I had changed all the 
stable versions at some point to have consistent --enable-doscompile 
handling (quite some time ago).  Are the tickets still accurate?  Does the 
problem only occur with OsIi?  I have no problems with other projects on 
Cygwin.

> 	Andreas, do you think we're ready to try the leap to autoconf 2.61?
> We'll need that to avoid known problems with dylp configuration and the cl
> compiler. If not, I'll back out to 2.59 locally and generate a new DyLP point
> release that's compatible with current CoinUtils.

If you are talking about the error message during configure with the 
"exit" declaration during the AC_TRY_LINK test, you can work around this 
by adding a first argument, such as

AC_TRY_LINK([void GreatFunction();], [GreatFunction()], ...)

This is what I did in the tests in coin.m4.

I would be hesitant to switch to newer versions of autoconf soon.  I would 
like to test things more before that happens.

> 	Short-term workaround is to use --enable-doscompile, so that CoinUtils
> builds with -mno-cygwin.

In order to find the problem, we need a case - for which project/version 
does it not work?

Thanks

Andreas