SCIP is an open source optimizer that solves Mixed Integer Programs (MIP). Since version 8.0.3 it is released under the Apache 2.0 license, making it available to a large variety of projects (a huge “thank you” to the SCIP team for this license choice!). I have experimented with using SCIP via the recently released version 1.4.0 of Rust’s good_lp.
What ended up being the smoothest course for me was building from source:
wget https://scipopt.org/download/release/scipoptsuite-8.0.3.tgz tar -xvzf scipoptsuite-8.0.3.tgz cd scipoptsuite-8.0.3 brew install bison brew install ipopt brew install tbb mkdir -p ~/lib/scip mkdir build cd build cmake -DCMAKE_INSTALL_PREFIX:PATH=$HOME/lib/scip .. make -j4 && make install export LIBRARY_PATH=$LIBRARY_PATH:$HOME/lib/scip/lib export DYLD_LIBRARY_PATH=$DYLD_LIBRARY_PATH:$HOME/lib/scip/lib
Below are two other methods, conda and binary bundles which did not result in a working library/binary for me.
Build with multi-threading support
To build with threading, configure the TPI parameter in CMake:
cmake -DCMAKE_INSTALL_PREFIX:PATH=$HOME/lib/scip -DTPI=tny ..
Does not work: binary bundles
The binary bundles appear to be compiled only for x86_64. You might have tried to install the 8.0.3 binary package from the website. The first hint is that installation instructions ask for brew install gcc@10, which results in the following error on arm64 Macs:
$ brew install gcc@10 gcc@10: The x86_64 architecture is required for this software. Error: gcc@10: An unsatisfied requirement failed this build.
Trying with gcc@11, the installed binary still expects x86_64:
$ brew install gcc@11 $ export DYLD_LIBRARY_PATH=$DYLD_LIBRARY_PATH:/opt/homebrew/Cellar/gcc@11/11.3.0/lib/gcc/11/ $ wget https://scipopt.org/download/release/SCIPOptSuite-8.0.3-Darwin-Ipopt-gcc10.sh $ chmod u+x SCIPOptSuite-8.0.3-Darwin-Ipopt-gcc10.sh $ ./SCIPOptSuite-8.0.3-Darwin-Ipopt-gcc10.sh --prefix=$HOME/lib --include-subdir $ /Users/yonch/lib/SCIPOptSuite-8.0.3-Darwin/bin/scip dyld[53260]: Library not loaded: /usr/local/opt/gcc/lib/gcc/10/libgfortran.5.dylib Referenced from: <646081BB-B4DB-3BA0-97D5-D97CF2622E2A> /Users/yonch/lib/SCIPOptSuite-8.0.3-Darwin/bin/scip Reason: tried: '/libgfortran.5.dylib' (no such file), '/opt/homebrew/Cellar/gcc@11/11.3.0/lib/gcc/11//libgfortran.5.dylib' (mach-o file, but is an incompatible architecture (have 'arm64', need 'x86_64'))
note the `(have ‘arm64’, need ‘x86_64’)`.
Fragile: conda install
Conda libraries do not seem 100% compatible with the packages provided with Xcode and other brew package, and this incompatibility resulted in missing link symbols.
$ brew install miniconda $ conda install --channel conda-forge scip $ export LIBRARY_PATH=$LIBRARY_PATH:/opt/homebrew/Caskroom/miniconda/base/lib/ $ export DYLD_LIBRARY_PATH=$DYLD_LIBRARY_PATH:/opt/homebrew/Caskroom/miniconda/base/lib/ $ cargo run dyld[44079]: Symbol not found: _iconv Referenced from: <15170D86-C5DF-3B69-90CE-63CC469F021F> /opt/homebrew/Cellar/rust/1.67.0/bin/cargo Expected in: <1DC18063-4642-3792-A05F-23DF6407E45B> /opt/homebrew/Caskroom/miniconda/base/lib/libiconv.2.dylib Abort trap: 6
The QGIS community apparently also experienced a similar problem with missing _iconv on MacOS. The accepted workaround was to copy the system’s lib from `/usr/lib/libiconv.2.dylib` and overriding the supplied library. I decided not to pursue the conda angle further and instead compile from source (described above).