external_deps: reformat and reword the help message

Print to stderr.
Reformat the help message.
Replace dynamic tabs with spaces.
Also simplify an overengineered madness.
Also we don't do zip anymore, tarball for everyone for a long time.

Author: illwieckz

external_deps/build.sh

@@ -1471,63 +1471,64 @@ all_windows_platforms='windows-amd64-mingw windows-amd64-msvc windows-i686-mingw
 all_macos_platforms='macos-amd64-default'
 all_platforms="${all_linux_platforms} ${all_windows_platforms} ${all_macos_platforms}"
 
-errorHelp() {
-	sed -e 's/\\t/'$'\t''/g' <<-EOF
-	usage: $(basename "${BASH_SOURCE[0]}") [OPTION] <PLATFORM> <PACKAGE[S]...>
+printHelp() {
+	# Please align to 4-space tabs.
+	cat >&2 <<-EOF
+	usage: $(basename "${BASH_SOURCE[0]}") [OPTION] <PLATFORM> <PACKAGE(S)...>
 
 	Script to build dependencies for platforms which do not provide them
 
 	Options:
-	\t--download-only — only download source packages, do not build them
-	\t--prefer-ours — attempt to download from unvanquished.net first
+	    --download-only only download source packages, do not build them
+	    --prefer-ours   attempt to download from unvanquished.net first
 
 	Platforms:
-	\t${all_platforms}
+	    ${all_platforms}
 
 	Virtual platforms:
-	\tlinux — ${all_linux_platforms}
-	\twindows — ${all_windows_platforms}
-	\tmacos — ${all_macos_platforms}
-	\tall — linux windows macos
+	    linux   ${all_linux_platforms}
+	    windows ${all_windows_platforms}
+	    macos   ${all_macos_platforms}
+	    all     linux windows macos
 
 	Packages:
-	\tpkgconfig nasm zlib gmp nettle curl sdl3 glew png jpeg webp openal ogg vorbis opus opusfile naclsdk wasisdk wasmtime
+	    pkgconfig nasm zlib gmp nettle curl sdl3 glew png jpeg webp openal ogg vorbis opus opusfile naclsdk wasisdk wasmtime
 
 	Virtual packages:
-	\tbase — build packages for pre-built binaries to be downloaded when building the game
-	\tall — build all supported packages that can possibly be involved in building the game
-	\tinstall — create a stripped down version of the built packages that CMake can use
-	\tpackage — create a zip/tarball of the dependencies so they can be distributed
-	\twipe — remove products of build process, excepting download cache but INCLUDING installed files. Must be last
+	    base    build packages for pre-built binaries to be downloaded when building the game
+	    all     build all supported packages that can possibly be involved in building the game
+	    install create a stripped down version of the built packages that CMake can use
+	    package create a tarball of the dependencies so they can be distributed
+	    wipe    remove products of build process, excepting download cache but INCLUDING installed files. Must be last
 
 	Packages required for each platform:
 
 	windows-amd64-msvc:
 	windows-i686-msvc:
-	\tbase: ${base_windows_amd64_msvc_packages}
-	\tall: same
+	    base    ${base_windows_amd64_msvc_packages}
+	    all     same
 
 	windows-amd64-mingw:
 	windows-i686-mingw:
-	\tbase: ${base_windows_amd64_mingw_packages}
-	\tall: same
+	    base    ${base_windows_amd64_mingw_packages}
+	    all     same
 
 	macos-amd64-default:
-	\tbase: ${base_macos_amd64_default_packages}
-	\tall: same
+	    base    ${base_macos_amd64_default_packages}
+	    all     same
 
 	linux-amd64-default:
-	\tbase: ${base_linux_amd64_default_packages}
-	\tall: ${all_linux_amd64_default_packages}
+	    base    ${base_linux_amd64_default_packages}
+	    all     ${all_linux_amd64_default_packages}
 
 	linux-i686-default:
-	\tbase: ${base_linux_i686_default_packages}
-	\tall: ${all_linux_i686_default_packages}
+	    base    ${base_linux_i686_default_packages}
+	    all     ${all_linux_i686_default_packages}
 
 	linux-arm64-default:
 	linux-armhf-default:
-	\tbase: ${base_linux_arm64_default_packages}
-	\tall: ${all_linux_arm64_default_packages}
+	    base    ${base_linux_arm64_default_packages}
+	    all     ${all_linux_arm64_default_packages}
 
 	EOF
 	false