Document how to use a non-detected Kerberos lib

[simmel]

Not sure about the placing or wording.

You can specify it both when you install it via pip but also when you install it from source. What do you think?

I was looking for this docs when I first tried to troubleshoot the macOS 11 issues but I couldn't figure it out. Thanks @jborean93 for mentioning it!

[jborean93]

This should be PATH_TO/lib/libgssapi.so with a note saying the extension is .dylib on macOS. You might also want to mention that krb5-config selected in PATH should be for the Kerberos library you wish to link against.

[simmel]

There are other usecases on Windows; mingw, MIT Kerberos for Windows etc. Hence the comment. It became too messy to list them all.

Can the comment be improved somehow and still be brief?

Re: PATH, yes. Or maybe specify hard path e.g. /path/to/you/krb5-config. What's best?

[jborean93]

There are other usecases on Windows; mingw, MIT Kerberos for Windows etc. Hence the comment. It became too messy to list them all.

I can't say I use this with Windows so I can't really speak more, I just think it should be more obvious that the default is libgssapi.so for Linux and libgssapi.dylib for macOS as per

python-gssapi/setup.py

Lines 186 to 192 in a7de108

	if opt.startswith('gssapi'):
	if os.name == 'nt':
	main_lib = '%s.dll' % opt
	if winkrb_path:
	main_path = os.path.join(winkrb_path, 'bin')
	else:
	main_lib = 'lib%s.so' % opt

.

Or maybe specify hard path e.g. /path/to/you/krb5-config

You need to make sure it's first in PATH. Your linker and compiler args can use the full path but setup.py calls krb5-config gssapi --prefix so you need to ensure the correct krb5-config is selected there.

[simmel]

You need to make sure it's first in PATH. Your linker and compiler args can use the full path but setup.py calls krb5-config gssapi --prefix so you need to ensure the correct krb5-config is selected there.

I totally missed that! Fixing.

[simmel]

I can't say I use this with Windows so I can't really speak more, I just think it should be more obvious that the default is libgssapi.so for Linux and libgssapi.dylib for macOS as per

I really don't think this is clearer @jborean93

[jborean93]

My main comment was to do document libgssapi.so and just add a comment saying this could be .dylib or something else on other platforms.

[frozencemetery]

In most cases, the issue is simply locating krb5-config, which will produce the right compiler/linker flags for us. Setting the compile/link/library flags manually shouldn't be required (outside of porting work). If that's not the behavior, we should fix it :)

I think we should reflect that in any install instructions: that mostly one just sets PATH, and mention that the other env vars exist. (It might be clearest not to even give usage examples for them, since it's potentially confusing.)

[simmel]

On Wed, 2021-01-13 at 08:13:32 -0800, Robbie Harwood wrote: In most cases, the issue is simply locating krb5-config, which will produce the right compiler/linker flags for us. Setting the compile/link/library flags manually shouldn't be required (outside of porting work). If that's not the behavior, we should fix it :)

That's a great attitude! But I don't think that's possible everywhere, especially for GSSAPI_MAIN_LIB. Look at https://github.com/pythongssapi/python-gssapi/blob/a7de10/setup.py#L158-L208 no where is it using PATH or krb5-config to locate the main lib (and I don't think it could without guessing a lot). So that means: $ export PATH=/usr/local/opt/heimdal/bin:$PATH $ python3 setup.py build […] $ otool -L build/lib.macosx-11-x86_64-3.9/gssapi/raw/mech_krb5.cpython-39-darwin.so build/lib.macosx-11-x86_64-3.9/gssapi/raw/mech_krb5.cpython-39-darwin.so: /System/Library/Frameworks/GSS.framework/Versions/A/GSS (compatibility version 1.0.0, current version 1.0.0) /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 1292.60.1) will never work. For GSSAPI_COMPILER_ARGS we see at https://github.com/pythongssapi/python-gssapi/blob/a7de10/setup.py#L111-L122 that for macOS and Windows (winkrb_path is set https://github.com/pythongssapi/python-gssapi/blob/a7de10/setup.py#L52-L65 ) we have statically specified where to look. Well, Windows does fall back to looking at PATH where kinit is and use that path but I'm not sure that counts as being able to specify it dynamically (since you might have MIT Kerberos installed but what to try a new version located at another place). For GSSAPI_LINKER_ARGS it's basically the same as for GSSAPI_COMPILER_ARGS: https://github.com/pythongssapi/python-gssapi/blob/a7de10/setup.py#L95-L109 Maybe removing the "else" in those if-statements and always running krb5-config will work but I'm not so sure of that either.

[simmel]

stale bot is nice (for people like me who are forgetful ; )

[simmel]

@jborean93 is my force push available in this PR or do I need to open a new one since stalebot closed it?

While helping a co-worker getting python-gssapi to build on his Mac we tried to only use GSSAPI_COMPILER_ARGS and GSSAPI_LINKER_ARGS and that works.

[jborean93]

I’m not sure sorry, that’s a question for @frozencemetery

[frozencemetery]

is my force push available in this PR or do I need to open a new one since stalebot closed it?

I can't reopen it (the button is greyed out) - it looks like you might've force-pushed already? If you're not able to reopen either, I think a new PR would be in order.