update INSTALL instructions for macOS

And tiny whitespace fixes.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

INSTALL

@@ -26,7 +26,7 @@ You keep it updated by doing:
     git checkout master
     git pull -r
     git submodule update
-    
+
 
 Our flavor of libdivecomputer
 -----------------------------
@@ -273,40 +273,31 @@ sudo ldconfig ~/src/install-root/lib
 Building Subsurface under MacOSX
 --------------------------------
 
-You have 2 options for the first time install, either using homebrew
+While it is possible to build all required components completely from source,
-or by manually building the dependencies from source, depending on
+at this point the preferred way to build Subsurface is to set up the build
-what else you have installed on your mac.
+infrastructure via Homebrew and then build the dependencies from source.
 
 0) You need to have XCode installed. The first time (and possibly after updating OSX)
 
-0.1) run "xcode-select --install"
+xcode-select --install
 
-homebrew option:
+1) install Homebrew (see https://brew.sh) and then the required build infrastructure:
 
-1) brew install autoconf automake libtool hidapi libusb libxml2 libxslt libzip openssl pkg-config libgit2 libssh2 libjpg libpng libmtp
+brew install autoconf automake libtool pkg-config gettext
 
-2) cd <repo>/..; bash <repo>/scripts/build.sh
+2) install Qt
 
+download the macOS installer from https://download.qt.io/official_releases/online_installers
+and use it to install the desired Qt version. At this point the latest Qt5 version is still
+preferred over Qt6.
 
-Manual option:
+3) now build Subsurface
-1) install pkg-config
 
-1.1) download http://sourceforge.net/projects/macpkg/files/PkgConfig/0.26/PkgConfig.pkg/download
+cd ~/src; bash subsurface/scripts/build.sh -build-deps
 
-1.2) run "PkgConfig.pkg"
+if you are building against Qt6 (still experimental) you can create a universal binary with
-
-1.3) run "sudo ln -s /opt/pkgconfig/bin/pkg-config /usr/local/bin/pkg-config"
-
-2) install autoconf tools
-
-2.1) curl -OL http://ftpmirror.gnu.org/autoconf/autoconf-latest.tar.gz
-
-2.2) tar -xzf autoconf-latest.tar.gz
-
-2.3) cd autoconf-*; ./configure && make && sudo make install; cd ..
-
-3) cd <repo>/..; bash <repo>/scripts/build.sh -build-deps -desktop
 
+cd ~/src; bash subsurface/scripts/build.sh -build-with-qt6 -build-deps -fat-build
 
 After the above is done, Subsurface.app will be available in the
 subsurface/build directory. You can run Subsurface with the command
@@ -316,7 +307,7 @@ A) open subsurface/build/Subsurface.app
 
 B) subsurface/build/Subsurface.app/Contents/MacOS/Subsurface
    the TAB key is your friend :-)
-   
+
 Debugging can be done with either Xcode or QtCreator.
 
 To install the app for all users, move subsurface/build/Subsurface.app to /Applications.

scripts/build.sh

@@ -71,7 +71,7 @@ while [[ $# -gt 0 ]] ; do
 			# use the same 3rd party set.
 			shift
 			SRC_DIR="$1"
-			;;			
+			;;
 		-build-deps)
 			# in order to build the dependencies on Mac for release builds (to deal with the macosx-version-min for those)
 			# call this script with -build-deps
@@ -112,7 +112,7 @@ while [[ $# -gt 0 ]] ; do
 		-mobile)
 			# we are building Subsurface-mobile
 			# Note that this will run natively on the host OS.
-			# To cross build for Android or iOS (including simulator) 
+			# To cross build for Android or iOS (including simulator)
 			# use the scripts in packaging/xxx
 			BUILD_MOBILE="1"
 			;;