Make dynlibs relative for OSX

.github/workflows/build-macos.yml

@@ -6,6 +6,10 @@ jobs:
   build:
     runs-on: macos-latest
     steps:
+    - uses: actions/checkout@v3
+      with:
+        submodules: false
+
     - uses: maxim-lobanov/setup-xcode@v1
       with:
         xcode-version: '13.1.0'
@@ -43,6 +47,13 @@ jobs:
         cp -a picotool /tmp/picotool/.
         cp -a ../LICENSE.TXT /tmp/picotool/.
         cp -a ../README.md /tmp/picotool/.
+
+        # Make dynlibs relative
+        otool -L /tmp/picotool/picotool
+        (cwd=$(pwd); cd /tmp/picotool; bash $cwd/osx-relative-dynlib.sh)
+        otool -L /tmp/picotool/picotool
+
+        # Create tarball
         tar cvf ../../picotool.macos.tar -C /tmp picotool
 
     - name: Upload Picotool

osx-relative-dynlib.sh

@@ -0,0 +1,43 @@
+#!/bin/bash -eu
+
+process_binary() {
+    local binary="$1"
+    echo "[*] Processing $binary..."
+
+    # Find all linked libraries from the Homebrew prefix
+    local libraries=(
+        $(otool -L "$binary" | grep '/usr/local/opt/' | awk '{print $1}')
+    )
+
+    # If this is a dylib, the first entry is the ID of the library itself, which
+    # we don't really care about.
+    if [ "${binary##*.}" = "dylib" ]; then
+        libraries=("${libraries[@]:1}")
+    fi
+
+    # When empty, skip the loop to avoid a Bash unbound variable error
+    if [ ${#libraries[@]} -le 0 ]; then
+        continue
+    fi
+
+    for lib in "${libraries[@]}"; do
+        local lib_basename=$(basename "$lib")
+
+        # Check that we have a copy of each linked library
+        if [ ! -f "$lib_basename" ]; then
+            echo "  [-] Failed to find linked library $lib_basename"
+            continue
+        fi
+
+        # Change the path to be relative
+        install_name_tool -change "$lib" "@executable_path/$lib_basename" \
+                          "$binary"
+        echo "  [+] Made relative link to $lib_basename"
+    done
+}
+
+
+for binary in *.dylib $(find . -type f -perm +111); do
+    process_binary "$binary"
+done
+