> at a guess it looks like the libtommath you installed wasn't build with =fPIC
> a must if you want to include its symbols in another shared library (Firebird)

> Perhaps it would be easier if you used the configure command --with-builtin-libtommath?

<<Thanks for getting back to me so quickly.

I'm not sure I understand. I actually did initially try --with-builtin-libtommath but that failed - I assumed because the library isn't present in the Firebird sources?

But it's wasn't present on my system either - when I installed it, the compilation went further than without it.

What will compiling now with --with-builtin-libtommath do that it didn't before?>>

if you do a ./configure --help
you will see that --with-builtin-libtommath "build libtommath library from the firebird tree"
This means the libtommath library should be built "within" firebird...
If you look in extern within your firebird code there should be a libtommath directory.
That code is used to build the libtommath library which will be linked into the firebird
shared library during compilation.

I know this works because there is no installed libtommath library on MacOS and I have to build
fireird this way so that firebird is dependent on some randomly installed 3rd party libtommath
library.

regards
Paul