Can't Find gfortran library

[jshan432]

Hello,

I am attempting to run SNOPT using the trial libraries. However, when calling SNOPT, the following error occurs.

LoadError: could not load library "/Users/lab_home/Documents/SNOPT/libsnopt7"
dlopen(/Users/lab_home/Documents/SNOPT/libsnopt7.dylib, 1): Library not loaded: /opt/local/lib/libgcc/libgfortran.5.dylib
Referenced from: /Users/lab_home/Documents/SNOPT/libsnopt7.dylib
Reason: image not found

It appears the snopt trial library is looking for the gfortran library in the wrong place? The /opt/local... directory doesn't actually exist on my Mac.

I appreciate any feedback you can give.

[gnowzil]

Hi, can you check that gfortran is installed on your computer? If which -a gfortran doesn't show anything, then it's not installed and I would recommend using either macports or homebrew to install on macos.

[jshan432]

Thank you for getting back to me.

which -a gfortran returns

/usr/local/bin/gfortran
/usr/local/Cellar/gcc/10.2.0/bin/gfortran

and libgfortran.5.dylib exists in /usr/local/Cellar/gcc/10.2.0/lib/gcc/10

[jshan432]

I found a work around for this issue, but now I get the following error:

ERROR: LoadError: could not load library "/Users/lab_home/Documents/SNOPT/libsnopt7_cpp"
dlopen(/Users/lab_home/Documents/SNOPT/libsnopt7_cpp.dylib, 1): Symbol not found: __ZNSt8ios_base4InitD1Ev
Referenced from: /Users/lab_home/Documents/SNOPT/libsnopt7_cpp.dylib
Expected in: flat namespace
in /Users/lab_home/Documents/SNOPT/libsnopt7_cpp.dylib

I appreciate your help.

[gnowzil]

I'm pretty sure in both cases it's due to compiler incompatibility. Our libraries were created using gcc9, it looks like you're using homebrew, which is using gcc10.

Let me get our libraries on gcc10 as well, since that is the current stable release.