Why Nauty sources are required to use external Nauty?

[yurivict]

Are Nauty headers+library not sufficient?

[benlorenz]

They should be sufficient, I will have a look if we can adjust this.
This option was probably not considered when the configuration scripts were written because nauty itself does not provide any installation targets in the makefile.

[yurivict]

[...] nauty itself does not provide any installation targets in the makefile.

This is true, but ports often install such projects. At least the FreeBSD port and Arch ports do that,

[benlorenz]

Please try this patch: https://polymake.org/downloads/libnauty.patch
This allows passing --with-nauty=/some/prefix to configure and adds some autodetection for system-wide nauty installations. The output should look somewhat like this:

bundled extension nauty ... ok (version 26041 @ system)

If the autodetection fails (and no --with-nauty=PATH is given) it will fall back to the bundled version and show (source: bundled).
Please post the contents of build/bundled.log if there are any unexpected errors.

PS: I hope that all those nauty-installation layouts do not differ too much, i.e. I am assuming that the headers live in a /some/path/include/nauty/ directory.

[yurivict]

@benlorenz The patch works, thank you.

[benlorenz]

Thanks for testing, we will include this in the next polymake release.