failed when I install pypcap on Mac with Python 2.7

[taisiting]

I need to install pypcap with Python 2 on Mac.
It failed when I use source install: python2 setup.py install

pcap_ex.c:292:10: warning: 'pcap_compile_nopcap' is deprecated: use pcap_open_dead(), pcap_compile() and pcap_close() [-Wdeprecated-declarations]
return (pcap_compile_nopcap(snaplen, dlt, fp, str, optimize, netmask));
^
/usr/local/include/pcap/pcap.h:617:1: note: 'pcap_compile_nopcap' has been explicitly marked deprecated here
PCAP_DEPRECATED("use pcap_open_dead(), pcap_compile() and pcap_close()")
^
/usr/local/include/pcap/funcattrs.h:307:47: note: expanded from macro 'PCAP_DEPRECATED'
#define PCAP_DEPRECATED(msg) attribute((deprecated(msg)))
^
2 warnings generated.
/usr/bin/clang -bundle -undefined dynamic_lookup -arch i386 -arch x86_64 -g build/temp.macosx-10.6-intel-2.7/pcap.o build/temp.macosx-10.6-intel-2.7/pcap_ex.o -L/usr/local/lib -lpcap -o build/lib.macosx-10.6-intel-2.7/pcap.so
ld: warning: The i386 architecture is deprecated for macOS (remove from the Xcode build setting: ARCHS)
ld: warning: ignoring file /usr/local/lib/libpcap.dylib, missing required architecture i386 in file /usr/local/lib/libpcap.dylib (2 slices)
ld: warning: ignoring file /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/lib/libSystem.tbd, missing required architecture i386 in file /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/lib/libSystem.tbd (3 slices)
ld: dynamic main executables must link with libSystem.dylib for architecture i386
clang: error: linker command failed with exit code 1 (use -v to see invocation)
error: command '/usr/bin/clang' failed with exit status 1

It also failed when I use pip install: pip2 install pypcap
/usr/local/include/pcap/pcap.h:394:1: note: 'pcap_lookupdev' has been explicitly marked deprecated here
PCAP_DEPRECATED("use 'pcap_findalldevs' and use the first device")
^
/usr/local/include/pcap/funcattrs.h:307:47: note: expanded from macro 'PCAP_DEPRECATED'
#define PCAP_DEPRECATED(msg) attribute((deprecated(msg)))
^
pcap_ex.c:292:10: warning: 'pcap_compile_nopcap' is deprecated: use pcap_open_dead(), pcap_compile() and pcap_close() [-Wdeprecated-declarations]
return (pcap_compile_nopcap(snaplen, dlt, fp, str, optimize, netmask));
^
/usr/local/include/pcap/pcap.h:617:1: note: 'pcap_compile_nopcap' has been explicitly marked deprecated here
PCAP_DEPRECATED("use pcap_open_dead(), pcap_compile() and pcap_close()")
^
/usr/local/include/pcap/funcattrs.h:307:47: note: expanded from macro 'PCAP_DEPRECATED'
#define PCAP_DEPRECATED(msg) attribute((deprecated(msg)))
^
2 warnings generated.
creating build/lib.macosx-10.6-intel-2.7
/usr/bin/clang -bundle -undefined dynamic_lookup -arch i386 -arch x86_64 -g build/temp.macosx-10.6-intel-2.7/pcap.o build/temp.macosx-10.6-intel-2.7/pcap_ex.o -L/usr/local/lib -lpcap -o build/lib.macosx-10.6-intel-2.7/pcap.so
ld: warning: The i386 architecture is deprecated for macOS (remove from the Xcode build setting: ARCHS)
ld: warning: ignoring file /usr/local/lib/libpcap.dylib, missing required architecture i386 in file /usr/local/lib/libpcap.dylib (2 slices)
ld: warning: ignoring file /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/lib/libSystem.tbd, missing required architecture i386 in file /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/lib/libSystem.tbd (3 slices)
ld: dynamic main executables must link with libSystem.dylib for architecture i386
clang: error: linker command failed with exit code 1 (use -v to see invocation)
error: command '/usr/bin/clang' failed with exit status 1

[guyharris]

warning: 'pcap_compile_nopcap' is deprecated: use pcap_open_dead(), pcap_compile() and pcap_close()

It's deprecated because, at least in some versions of NetBSD, it has a different function signature ("different" as in "different number of arguments") from the one in libpcap and other platforms. pcap_open_dead(), pcap_compile(), and pcap_close() do not have that problem.

if pypcap can switch to using those routines if pcap_open_dead() is available, it should. If it can't, because it's directly exporting a pcap_compile_nopcap-based API, it should somehow deal with API differences in libpcap.

note: 'pcap_lookupdev' has been explicitly marked deprecated here

That one's even worse - it's not thread-safe (I guess making its static data thread-local would fix that), and, if you support Windows, it returns UTF-16 strings, at least on NT-based Windows - not ASCII/UTF-8/local code page strings - and changing that would break binary compatibility with programs using WinPcap or Npcap.

If pypcap can switch to, as the deprecation warning says, "[using] 'pcap_findalldevs' and [using] the first device", it should. If it can't, because it's directly exporting a pcap_lookupdev-based API and can't implement it atop pcap_findalldevs(), it should deprecate that API and say "watch out on Windows!"

/usr/bin/clang -bundle -undefined dynamic_lookup -arch i386 -arch x86_64 ...

That probably will not work on Catalina or later, as they don't support 32-bit binaries, meaning none of the system libraries include 32-bit x86 code.

If pypcap defaults to building universal binaries, it should not do so on Catalina, and should build x86-64/ARM64 universal binaries, not IA-32/x86-64 universal binaries, on post-Catalina releases.

If pypcap doesn't default to building universal binaries, people trying to install pypcap shouldn't do anything that would override that if they're building on Catalina or later.

[guyharris]

(Unless the universal-binary problem is a Python 2/pip2 problem.)

[taisiting]

My macOS is Monterey 12.6.5, It's successful with "pip2 install pypcap" on my another macOS Big Sur.

So may I try to reinstall python 2.7/pip2 on my first macOS?

[taisiting]

I solve it, thanks also.
My macOS is Monterey 12.6.5, it removes [Python 2.7]。 I download "python-2.7.14-macosx10.6.pkg" and it makes the above issue。
I uninstall the "python-2.7.14-macosx10.6.pkg" and reinstall "python-2.7.18-macosx10.9.pkg" then it works. (Reference to https://apple.stackexchange.com/questions/438427/restore-python-2-7-on-monterey-12-3)

pip2 install pypcap
DEPRECATION: Python 2.7 will reach the end of its life on January 1st, 2020. Please upgrade your Python as Python 2.7 won't be maintained after that date. A future version of pip will drop support for Python 2.7. More details about Python 2 support in pip, can be found at https://pip.pypa.io/en/latest/development/release-process/#python-2-support
Collecting pypcap
Using cached https://files.pythonhosted.org/packages/db/4f/419ad9b163f3e86c32ae3b1e2937709520e24dce589897a26fb875189520/pypcap-1.3.0.tar.gz
Installing collected packages: pypcap
Running setup.py install for pypcap ... done
Successfully installed pypcap-1.3.0
WARNING: You are using pip version 19.2.3, however version 20.3.4 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.