Thank you, Brian and Ryan, for your analysis. Ken Wolcott
On Wed, Jan 1, 2025 at 3:02 AM Ryan Carsten Schmidt <ryandes...@macports.org> wrote: > On Dec 31, 2024, at 19:06, Kenneth Wolcott wrote: > > > > 3. MacPorts port: nim > > 4. nimble is the Nim package manager which comes with the nim port. > > 4. nimble install bignum (seems to successfully install, but I wonder > if it is silently installing an x86-64 pre-compiled binary??) > > 5. compile using: nim c ./arithmetic_geometric_mean_calculate_pi > > 6. execute: ./arithmetic_geometric_mean_calculate_pi > > I agree, on my Intel Mac with macOS 12 this produces: > > could not load: libgmp.dylib > (compile with -d:nimDebugDlOpen for more information) > > However it succeeds if I run it this way: > > DYLD_FALLBACK_LIBRARY_PATH=/opt/local/lib > ./arithmetic_geometric_mean_calculate_pi > > Computed 25000 digits in 103 ms > π = 3.141592653589793238...81377399510065895288... > > Anytime a program requires you to set DYLD_LIBRARY_PATH or > DYLD_FALLBACK_LIBRARY_PATH, the developers are doing it wrong. > > The gmp nimble module that the bignum nimble module is using evidently > tries to use the gmp library by dlopening it. On macOS, it is necessary to > pass the absolute path to the library to be opened, and they are evidently > not doing that and are only passing the library name. That may be common on > Linux but it is not done that way on macOS. macOS is not Linux. > > Using dlopen at all is not recommended on macOS and has worse performance > than doing it the "normal" way, which is to link with the dynamic library. > > I'm not sure whether the bug is only in the gmp nimble module or is more > pervasive. In searching for this error, I've found reports of it with other > libraries as well. It may be a design flaw in nimble or nim that needs a > central solution. > > I did not find a bug report tracking this problem. I found many reports of > problems like this but they all end with the suggestion to set the > environment variable, which is just a workaround and not a fix. >
