xmlsec package includes references to homebrew (?)

[nxg]

(This is a hesitant report: I'm not 100% sure about where the issue is attributable to. Also, I'm guessing that apparent problems with the xmlsec PyPI packages would be reportable here – please redirect me if that's wrong.)

This is on macOS 15.4, which provides Python 3.9.6.

After I install xmlsec (1.3.15) into a venv, from PyPI, I'm unable to import it because, it appears, it contains references to homebrew libraries which don't exist.

% python
Python 3.9.6 (default, Mar 12 2025, 20:22:46) 
[Clang 17.0.0 (clang-1700.0.13.3)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import xmlsec
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: dlopen([PATH-TO-VENV]/lib/python3.9/site-packages/xmlsec.cpython-39-darwin.so, 0x0002): Library not loaded: /opt/homebrew/opt/libxmlsec1/lib/libxmlsec1-openssl.1.dylib
  Referenced from: <FD0F84B5-77CB-3D58-9D97-52ECC5125326> [PATH-TO-VENV]/lib/python3.9/site-packages/xmlsec.cpython-39-darwin.so
  Reason: tried: '/opt/homebrew/opt/libxmlsec1/lib/libxmlsec1-openssl.1.dylib' (no such file), '/System/Volumes/Preboot/Cryptexes/OS/opt/homebrew/opt/libxmlsec1/lib/libxmlsec1-openssl.1.dylib' (no such file), '/opt/homebrew/opt/libxmlsec1/lib/libxmlsec1-openssl.1.dylib' (no such file)
>>> 

And sure enough, if I use dyld_info to look at the libraries that library loads, they refer to homebrew (see below), and this is corroborated (also below) by looking at the load commands using otool -l (there, I notice also a reference to /Users/amin which suggests this may not have been build in an entirely clean environment). There is no homebrew cryptex on the machine, and no /opt/homebrew.

I have had homebrew on this machine, but deleted it, which meant that my first suspicion was that there was some hangover from that, that was messing with the dyld load path (and it's been a while since I had to be fully familiar with dyld's gymnastics). But I don't think that's the explanation, since this was a pip binary install (also there's no user amin on my machine, ruling out that path being synthesised dynamically).

I tried a --no-binary install of xmlsec, but it failed (the docs note that this is a tricky build). That's fine – I'd rather install a PyPI binary than attempt to integrate a non-trivial build into my current build-system.

Thus it appears that the PyPI package depends on a homebrew library which is present on the package build machine, but not on mine. My hesitation is because I've never had to become familiar with the internal details of Python package building, and because I'm aware dyld has tricked me in the past, so I'm reluctant to make confident statements here.

% dyld_info [PATH-TO-VENV]/lib/python3.9/site-packages/xmlsec.cpython-39-darwin.so
[PATH-TO-VENV]/lib/python3.9/site-packages/xmlsec.cpython-39-darwin.so [arm64]:
    -platform:
        platform     minOS      sdk
           macOS     13.3      15.2   
    -uuid:
        FD0F84B5-77CB-3D58-9D97-52ECC5125326
    -segments:
        load-offset   segment  section       sect-size  seg-size   init/max-prot
        0x00000000    __TEXT                                64KB    r.x/r.x
        0x00001A78             __text            33340
        0x00009CB4             __stubs            2592
        0x0000A6D4             __stub_helper      2616
        0x0000B10C             __cstring         11447
        0x0000DDC3             __const            8394
        0x0000FE90             __unwind_info       368
        0x00010000    __DATA_CONST                          16KB    rw./rw.
        0x00010000             __got               400
        0x00014000    __DATA                                32KB    rw./rw.
        0x00014000             __la_symbol_ptr    1728
        0x000146C0             __data            20832
        0x00019820             __bss               408
        0x000199B8             __common             24
    -linked_dylibs:
        attributes     load path
                       /opt/homebrew/opt/libxmlsec1/lib/libxmlsec1-openssl.1.dylib
                       /opt/homebrew/opt/libxmlsec1/lib/libxmlsec1.1.dylib
                       /opt/homebrew/opt/openssl@3/lib/libcrypto.3.dylib
                       /usr/lib/libxslt.1.dylib
                       /usr/lib/libxml2.2.dylib
                       /usr/lib/libSystem.B.dylib

Checking the load commands seems to corroborate this:

% otool -l [PATH-TO-VENV]/lib/python3.9/site-packages/xmlsec.cpython-39-darwin.so
[PATH-TO-VENV]/lib/python3.9/site-packages/xmlsec.cpython-39-darwin.so:

[...blah blah...]
Load command 10
          cmd LC_LOAD_DYLIB
      cmdsize 88
         name /opt/homebrew/opt/libxmlsec1/lib/libxmlsec1-openssl.1.dylib (offset 24)
   time stamp 2 Thu Jan  1 01:00:02 1970
      current version 5.7.0
compatibility version 5.0.0
Load command 11
          cmd LC_LOAD_DYLIB
      cmdsize 80
         name /opt/homebrew/opt/libxmlsec1/lib/libxmlsec1.1.dylib (offset 24)
   time stamp 2 Thu Jan  1 01:00:02 1970
      current version 5.7.0
compatibility version 5.0.0
Load command 12
          cmd LC_LOAD_DYLIB
      cmdsize 80
         name /opt/homebrew/opt/openssl@3/lib/libcrypto.3.dylib (offset 24)
   time stamp 2 Thu Jan  1 01:00:02 1970
      current version 3.0.0
compatibility version 3.0.0
Load command 13
          cmd LC_LOAD_DYLIB
      cmdsize 56
         name /usr/lib/libxslt.1.dylib (offset 24)
   time stamp 2 Thu Jan  1 01:00:02 1970
      current version 3.26.0
compatibility version 3.0.0
Load command 14
          cmd LC_LOAD_DYLIB
      cmdsize 56
         name /usr/lib/libxml2.2.dylib (offset 24)
   time stamp 2 Thu Jan  1 01:00:02 1970
      current version 10.9.0
compatibility version 10.0.0
Load command 15
          cmd LC_LOAD_DYLIB
      cmdsize 56
         name /usr/lib/libSystem.B.dylib (offset 24)
   time stamp 2 Thu Jan  1 01:00:02 1970
      current version 1351.0.0
compatibility version 1.0.0
Load command 16
          cmd LC_RPATH
      cmdsize 56
         path /Users/amin/.pyenv/versions/3.9.11/lib (offset 12)
Load command 17
          cmd LC_RPATH
      cmdsize 32
         path /opt/homebrew/lib (offset 12)
Load command 18
      cmd LC_FUNCTION_STARTS
  cmdsize 16
  dataoff 124448
 datasize 208
Load command 19
      cmd LC_DATA_IN_CODE
  cmdsize 16
  dataoff 124656
 datasize 0
Load command 20
      cmd LC_CODE_SIGNATURE
  cmdsize 16
  dataoff 169904
 datasize 1480