[Coin-ipopt] Cygwin and Ipopt-3.2.3

Andreas Waechter andreasw at watson.ibm.com
Tue Dec 19 10:07:27 EST 2006

Hi Paulo,

I'm cc-ing the mailing list, since I realized that this might be of 
broader interest.

> Your guess was right. The problem is in the zip file.
> I have recompiled Ipopt from the tgz file and it compiled fine.

Thank you for confirming that the .zip files in 
www.coin-or.org/Tarballs/Ipopt are not working correctly.  I will try to 
have that fixed soon.

> One or two minor comments:
> Ipopt-3.1.0 did not require any Cygwin dll to run; this means that you
> could simply run AMPL from a command console under Windows and Ipopt
> would run fine.
> Ipopt-3.2.3 requires cygwin1.dll if you want to run it outside the
> cygwin environment. One side effect of this (a strange one) is that you
> loose the capability of copy/paste from the console window once you
> invoke Ipopt.
> One can run AMPL under sw.exe to retain the copy/past facilities (but
> this Windows console program does not have the handy feature of column
> copy/paste...).

I guess I never stated explicitly that some default configuration has 
changed for Cygwin (which was a COIN-wide decision):

Under Cygwin, with the GNU compilers, one has the option to compile the 
code with the -mno-cygwin compiler flag.  If that flag is used, the 
generated code will use the Windows system calls directly; if the flag is 
omitted, then the generated executable will use the cygwin1.dll (for 
things like IO, etc.).

Previously, we would always use the -mno-cygwin compiler flag under 
Cygwin (so that people can run the executables directly under DOS). 
However, when the configuration scripts started to be used COIN-wide, 
people wanted to have the option to choose, and to have the "native 
Cygwin" mode as default.

However, you can still configure Ipopt under Cygwin so that it doesn't 
depend on cygwin1.dll, by specifying the '--enable-doscompile' configure 

Please give that a try for your Ipopt-3.2.3 version.  If you still need 
cygwin1.dll then, please let me know, because that would be a bug in the 
configuration scripts.

Many thanks,


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