pkg/56064: security/libgcrypt problems on macOS/M1

[gson%gson.org@localhost (Andreas Gustafsson)]

>Number:         56064
>Category:       pkg
>Synopsis:       security/libgcrypt problems on macOS/M1
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    pkg-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Mar 19 08:35:00 +0000 2021
>Originator:     Andreas Gustafsson
>Release:        macOS Big Sur 11.2.3
>Organization:
  
>Environment:
System: macOS
Architecture: aarch64
Machine: aarch64
>Description:

Using pkgsrc-current on macOS Big Sur 11.2.3 on the ARM-based Mac mini M1,
importing the Python module lxml.etree fails with a libgcrypt related error:

  $ python3.8 -c 'import lxml.etree'
  Traceback (most recent call last):
    File "<string>", line 1, in <module>
  ImportError: dlopen(/Users/gson/pkg/lib/python3.8/site-packages/lxml/etree.so, 2): Symbol not found: __gcry_mpih_add_n
    Referenced from: /Users/gson/pkg/lib/libgcrypt.20.dylib
    Expected in: flat namespace
   in /Users/gson/pkg/lib/libgcrypt.20.dylib

Also, the build of security/libgcrypt prints a number of warnings,
such as:

  ld: warning: arm64 function not 4-byte aligned: _gcry_mpih_add_n from ../mpi/.libs/libmpi.a(mpih-add1-asm.o)
  ld: warning: arm64 function not 4-byte aligned: .Loop from ../mpi/.libs/libmpi.a(mpih-add1-asm.o)
  ld: warning: arm64 function not 4-byte aligned: .Large_loop from ../mpi/.libs/libmpi.a(mpih-add1-asm.o)
  ld: warning: arm64 function not 4-byte aligned: .Lend from ../mpi/.libs/libmpi.a(mpih-add1-asm.o)
  ld: warning: arm64 function not 4-byte aligned: _gcry_mpih_sub_n from ../mpi/.libs/libmpi.a(mpih-sub1-asm.o)
  ld: warning: arm64 function not 4-byte aligned: .Loop from ../mpi/.libs/libmpi.a(mpih-sub1-asm.o)
  [etc]

As a work-around, uncommenting the line

  CONFIGURE_ARGS+=        --disable-asm

in the libgcrypt package Makefile makes the lxml.etree import succeed.

>How-To-Repeat:

>Fix: