enhance(main/dart): enable auto updates

[TomJo2000]

I also took the opportunity to do some miscellaneous build script cleanup,
switching to the GitHub source also allows us to enable auto updates for dart.

PR checklist

• Builds locally
• Builds on CI
• Package content is complete
• Tested on Device

I would appreciate it if @priyanuj-gogoi could check this over,
reviews from anyone else are of course welcome as always.

[samujjal-gogoi]

I would appreciate it if @priyanuj-gogoi could check this over

Yes, I'll surely love to do the review!

PS: I'm @priyanuj-gogoi (Using a different account)

[samujjal-gogoi]

Use https://storage.googleapis.com/dart-archive/channels/stable/release/latest/VERSION (official) instead of the GitHub API to fetch latest stable dart version.

The response of that GitHub API URL is too large and you've to filter the latest release later in which case it's not ideal.

[samujjal-gogoi]

Although this regex pattern is valid but it's not sed compatible (like \d is not supported, + should be \+).

Prefer [0-9]\+\.[0-9]\+\.[0-9]\+.

[Biswa96]

That check is done here.

termux-packages/scripts/updates/utils/termux_pkg_upgrade_version.sh

Lines 20 to 32 in 388cd7e

	# If needed, filter version numbers using grep regexp.
	if [[ -n "${TERMUX_PKG_UPDATE_VERSION_REGEXP:-}" ]]; then
	# Extract version numbers.
	local OLD_LATEST_VERSION="${LATEST_VERSION}"
	LATEST_VERSION="$(grep -oP "${TERMUX_PKG_UPDATE_VERSION_REGEXP}" <<< "${LATEST_VERSION}" || true)"
	if [[ -z "${LATEST_VERSION:-}" ]]; then
	termux_error_exit <<-EndOfError
	ERROR: failed to filter version numbers using regexp '${TERMUX_PKG_UPDATE_VERSION_REGEXP}'.
	Ensure that it works correctly with ${OLD_LATEST_VERSION}.
	EndOfError
	fi
	unset OLD_LATEST_VERSION
	fi

[samujjal-gogoi]

I'm facing an error with the sed expression.

sed: -e expression #1, char 23: invalid reference \1 on `s' command's RHS

Perhaps, you've forgotten to add the group construct? i.e

"s|.*\(${TERMUX_PKG_UPDATE_VERSION_REGEXP}\)\"|\1|p"

[samujjal-gogoi]

Consider removing termux_step_pre_configure() since it's not required now and has been a bloat code for months (see io.dart file, there are no references of requiring any path fixes.)

[samujjal-gogoi]

So, I've tried testing the build artifact and looks like the build built 3.6.0 instead of the stable release.

You can verify it by yourself:

cat $PREFIX/lib/dart-sdk/version

---

The fetch dart shouldn't be executed in post source get (since we already cloned the repo).