[Ipopt] IPOPT install problem

[Xin He]

Dear all

I am trying to install IPOPT on my mac and I met some problem. The
error is following:

Visitors-iMac:Ipopt-3.12.1 Nacional$ make install
Making install in ThirdParty/ASL
test -z "/opt/software/Ipopt-3.12.1/install/lib" ||
/opt/software/Ipopt-3.12.1/ThirdParty/ASL/install-sh -d
"/opt/software/Ipopt-3.12.1/install/lib"
mkdir: /opt/software/Ipopt-3.12.1/install: File exists
make[2]: *** [install-exec-local] Error 1
make[1]: *** [install-am] Error 2
make: *** [install-recursive] Error 1

Does anyone know how to solve this install problems?
Thanks

H.X.