Add macOS packaging script

This script is a modified version of the Linux one, with a couple of tweaks to get them to look the same (Mach-O strip can’t --verbose?)

devtools/local-package-for-macos.sh

@@ -0,0 +1,73 @@
+set -e
+
+# This script builds a publishable release-worthy version of exa.
+# It gets the version number, builds exa using cargo, tests it, strips the
+# binary, and compresses it into a zip.
+#
+# It’s *mostly* the same as dev-package-for-linux.sh, except with some
+# Mach-specific things (otool instead of ldd), BSD-coreutils-specific things,
+# and it doesn’t run the xtests.
+
+
+# Virtualising macOS is a legal minefield, so this script is ‘local’ instead
+# of ‘dev’: I run it from my actual machine, rather than from a VM.
+uname=`uname -s`
+if [[ "$uname" != "Darwin" ]]; then
+  echo "Gotta be on Darwin to run this (detected '$uname')!"
+  exit 1
+fi
+
+# First, we need to get the version number to figure out what to call the zip.
+# We do this by getting the first line from the Cargo.toml that matches
+# /version/, removing its whitespace, and building a command out of it, so the
+# shell executes something like `exa_version="0.8.0"`, which it understands as
+# a variable definition. Hey, it’s not a hack if it works.
+#
+# Because this can’t use the absolute /vagrant path, this has to use what this
+# SO answer calls a “quoting disaster”: https://stackoverflow.com/a/20196098/3484614
+# You will also need GNU coreutils: https://stackoverflow.com/a/4031502/3484614
+exa_root="$(dirname "$(dirname "$(greadlink -fm "$0")")")"
+toml_file="$exa_root"/Cargo.toml
+eval exa_$(grep version $toml_file | head -n 1 | sed "s/ //g")
+if [ -z "$exa_version" ]; then
+  echo "Failed to parse version number! Can't build exa!"
+  exit 1
+else
+  echo "Building exa v$exa_version"
+fi
+
+# Compilation is done in --release mode, which takes longer but produces a
+# faster binary.
+echo -e "\n\033[4mCompiling release version of exa...\033[0m"
+exa_macos_binary="$exa_root/exa-macos-x86_64"
+rm -vf "$exa_macos_binary" | sed 's/^/removing /'
+cargo build --release --manifest-path "$toml_file"
+cargo test --release --manifest-path "$toml_file" --lib -- --quiet
+# we can’t run the xtests outside the VM!
+#/vagrant/xtests/run.sh --release
+cp "$exa_root"/target/release/exa "$exa_macos_binary"
+
+# Stripping the binary before distributing it removes a bunch of debugging
+# symbols, saving some space.
+echo -e "\n\033[4mStripping binary...\033[0m"
+strip "$exa_macos_binary"
+echo "strip $exa_macos_binary"
+
+# Compress the binary for upload. The ‘-j’ flag is necessary to avoid the
+# current path being in the zip too. Only the zip gets the version number, so
+# the binaries can have consistent names, and it’s still possible to tell
+# different *downloads* apart.
+echo -e "\n\033[4mZipping binary...\033[0m"
+exa_macos_zip="$exa_root/exa-macos-x86_64-${exa_version}.zip"
+rm -vf "$exa_macos_zip" | sed 's/^/removing /'
+zip -j "$exa_macos_zip" "$exa_macos_binary"
+
+# There was a problem a while back where a library was getting unknowingly
+# *dynamically* linked, which broke the whole ‘self-contained binary’ concept.
+# So dump the linker table, in case anything unscrupulous shows up.
+echo -e "\n\033[4mLibraries linked:\033[0m"
+otool -L "$exa_macos_binary" | sed 's/^[[:space:]]*//'
+
+# Might as well use it to test itself, right?
+echo -e "\n\033[4mAll done! Files produced:\033[0m"
+"$exa_macos_binary" "$exa_macos_binary" "$exa_macos_zip" -lB