Build the PAM module on macOS (0.10.1)

Cargo names a cdylib .dylib on macOS, so copying libahfail_pam.so out of
the target directory failed there, as the first real macOS build in the
Homebrew tap's Actions showed. The installed name stays .so.

Claude-Session: https://claude.ai/code/session_012LCTmU2ewo8tnM1dByYAoG

Cargo.lock

@@ -10,7 +10,7 @@ checksum = "320119579fcad9c21884f5c4861d16174d0e06250625266f50fe6898340abefa"
 
 [[package]]
 name = "ahfail"
-version = "0.10.0"
+version = "0.10.1"
 dependencies = [
  "ahfail-ui",
  "cc",

crates/ahfail/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ahfail"
-version = "0.10.0"
+version = "0.10.1"
 edition = "2021"
 description = "Screen locker that says ah ah ah when you get the password wrong"
 license = "AGPL-3.0-only"

meson.build

@@ -1,7 +1,7 @@
 project(
   'ahfail',
   ['c', 'rust'],
-  version: '0.10.0',
+  version: '0.10.1',
   meson_version: '>=1.3.0',
   default_options: ['warning_level=3', 'c_std=c11']
 )
@@ -36,8 +36,11 @@ is_linux = host_machine.system() == 'linux'
 cargo_pkgs = '-p ahfail-gtklock -p ahfail-pam -p ahfail-display' + (is_linux ? ' -p ahfail' : '')
 cargo_outputs = ['libahfail_module.a', 'libahfail_pam.so', 'ahfail-display'] + (is_linux ? ['ahfail'] : [])
 cargo_install_dirs = [false, get_option('libdir') / 'ahfail', get_option('libdir') / 'ahfail'] + (is_linux ? [get_option('bindir')] : [])
+# Cargo names a cdylib .dylib on macOS. The installed name stays
+# libahfail_pam.so: PAM loads the module by path, whatever the extension.
+pam_built = host_machine.system() == 'darwin' ? 'libahfail_pam.dylib' : 'libahfail_pam.so'
 cargo_copy = (' && cp "@OUTDIR@/target/release/libahfail_module.a" "@OUTPUT0@"'
-  + ' && cp "@OUTDIR@/target/release/libahfail_pam.so" "@OUTPUT1@"'
+  + ' && cp "@OUTDIR@/target/release/' + pam_built + '" "@OUTPUT1@"'
   + ' && cp "@OUTDIR@/target/release/ahfail-display" "@OUTPUT2@"'
   + (is_linux ? ' && cp "@OUTDIR@/target/release/ahfail" "@OUTPUT3@"' : ''))