Tweaks to the build script and building instructions

BUILDING.md

@@ -46,7 +46,20 @@ To build and configure the libraries Session uses, just run:
 pod install
 ```
 
-## 4. Xcode
+## 4. libSession build dependencies
+
+The iOS project has a share C++ library called `libSession` which is built as one of the project dependencies, in order for this to compile the following dependencies need to be installed:
+- cmake
+- m4
+- pkg-config
+
+These can be installed with Homebrew via `brew install cmake m4 pkg-config`
+
+Additionally `xcode-select` needs to be setup correctly (depending on the order of installation it can point to the wrong directory and result in a build error similar to `tool '{name}' requires Xcode, but active developer directory '/Library/Developer/CommandLineTools' is a command line tools instance`), this can be setup correctly by running:
+
+`sudo xcode-select -s /Applications/Xcode.app/Contents/Developer`
+
+## 5. Xcode
 
 Open the `Session.xcworkspace` in Xcode.
 
@@ -67,6 +80,9 @@ Build and Run and you are ready to go!
 
 ## Known issues
 
+### Third-party Installation
+The database for the app is stored within an `App Group` directory which is based on the app identifier, unfortunately the identifier cannot be retrieved at runtime so it's currently hard-coded in the code. In order to be able to run session on a device you will need to update the `UserDefaults.applicationGroup` variable in `SessionUtilitiesKit/General/SNUserDefaults` to match the value provided (You may also need to create the `App Group` on your Apple Developer account).
+
 ### Push Notifications
 Features related to push notifications are known to be not working for
 third-party contributors since Apple's Push Notification service pushes

Scripts/build_libSession_util.sh

@@ -27,6 +27,7 @@
 
 # Need to set the path or we won't find cmake
 PATH=${PATH}:/usr/local/bin:/opt/local/bin:/opt/homebrew/bin:/opt/homebrew/opt/m4/bin:/sbin/md5
+required_packages=("cmake" "m4" "pkg-config")
 
 exec 3>&1 # Save original stdout
 
@@ -34,15 +35,23 @@ exec 3>&1 # Save original stdout
 mkdir -p "${TARGET_BUILD_DIR}/libSessionUtil"
 
 echo "Validating build requirements"
+missing_packages=()
 
-# Ensure the build directory exists (in case we need it before XCode creates it)
-mkdir -p "${TARGET_BUILD_DIR}"
+for package in "${required_packages[@]}"; do
+  if ! which "$package" > /dev/null; then
+    missing_packages+=("$package")
+  fi
+done
 
-if ! which cmake > /dev/null; then
-  echo "error: cmake is required to build, please install (can install via homebrew with 'brew install cmake')."
-  exit 0
+if [ ${#missing_packages[@]} -ne 0 ]; then
+  packages=$(echo "${missing_packages[@]}")
+  echo "error: Some build dependencies are not installed, please install them ('brew install ${packages}'):"
+  exit 1
 fi
 
+# Ensure the build directory exists (in case we need it before XCode creates it)
+mkdir -p "${TARGET_BUILD_DIR}"
+
 # Check if we have the `LibSession-Util` submodule checked out and if not (depending on the 'SHOULD_AUTO_INIT_SUBMODULES' argument) perform the checkout
 if [ ! -d "${SRCROOT}/LibSession-Util" ] || [ ! -d "${SRCROOT}/LibSession-Util/src" ] || [ ! "$(ls -A "${SRCROOT}/LibSession-Util")" ]; then
   echo "error: Need to fetch LibSession-Util submodule (git submodule update --init --recursive)."
@@ -188,6 +197,8 @@ if [ "$CONFIGURATION" == "Debug" ]; then
     submodule_check=OFF
 fi
 
+echo "CMake build logs: ${TARGET_BUILD_DIR}/libSessionUtil/libsession_util_output.log"
+
 # Build the individual architectures
 for i in "${!TARGET_ARCHS[@]}"; do
     build="${TARGET_BUILD_DIR}/libSessionUtil/${TARGET_ARCHS[$i]}"