MacOS wheels: attempt to use cross-files to find pcap-config

.ci/before_all_macos.sh

@@ -7,12 +7,12 @@ pcap_version=1.10.4
 # TODO: pin specific versions
 brew install boost libdivide
 
-# Install pkgconfig from source twice - once for x86_64 and once for arm64.
+# Install pkgconfig from source - once for each architecture in CIBW_ARCHS
 cd /tmp
 wget --progress=dot:mega https://www.tcpdump.org/release/libpcap-${pcap_version}.tar.gz
 tar -zxf /tmp/libpcap-${pcap_version}.tar.gz
 cd libpcap-${pcap_version}/
-for arch in x86_64 arm64; do
+for arch in $CIBW_ARCHS; do
     mkdir build-$arch
     cd build-$arch
     if [ "$arch" == "x86_64" ]; then  # TODO: use `arch` to auto-detect cross-compilation
@@ -30,5 +30,6 @@ for arch in x86_64 arm64; do
     cd ..
 done
 
+# TODO: this is debugging
 echo $PATH
 pcap-config --cflags --libs

.ci/before_build_macos.sh

@@ -0,0 +1,14 @@
+#!/bin/bash
+set -e -u
+
+project="$1"
+
+# Set up meson cross file to pick up pcap-config. Meson refuses to use the one
+# in $PATH when cross-compiling.
+cat > "$project/pcap-cross.ini" <<EOF
+[binaries]
+pcap-config = /tmp/cibuildwheel/$CIBW_ARCHS/bin/pcap-config
+EOF
+
+# TODO this is debugging
+cat "$project/pcap-cross.ini"

pyproject.toml

@@ -98,11 +98,13 @@ before-all = ".ci/before_all_linux.sh"
 setup-args = [
   "-Dpcap=enabled",
   "-Db_lto=true",
+  "--cross-file=pcap-cross.ini",
 ]
 
 [tool.cibuildwheel.macos]
 archs = ["x86_64", "arm64"]
 before-all = ".ci/before_all_macos.sh"
+before-build = ".ci/before_build_macos.sh"
 # To ensure that the brew-installed libpcap gets picked up
 environment = { PKG_CONFIG_PATH="/usr/local/opt/libpcap/lib/pkgconfig" }