refactor(auto update): replace `pkg_dir` with `TERMUX_PKG_BUILDER_DIR`

- this variable will store path of directory containing packages
  `build.sh` file.
- this is a more standard approach than specifying `pkg_dir` each time

Signed-off-by: Aditya Alok <dev.aditya.alok@gmail.com>

packages/erlang/build.sh

@@ -23,7 +23,7 @@ termux_pkg_auto_update() {
 	tag="$(termux_github_api_get_tag "${TERMUX_PKG_SRCURL}")"
 	# check if this is not an intermediate release candidate:
 	if grep -qP "^OTP-${TERMUX_PKG_UPDATE_VERSION_REGEXP}\$" <<<"$tag"; then
-		pkg_dir=$(dirname "$0") termux_pkg_upgrade_version "$tag"
+		termux_pkg_upgrade_version "$tag"
 	else
 		echo "WARNING: Skipping auto-update: Not stable release($tag)"
 	fi

packages/libmsgpack-cxx/build.sh

@@ -16,7 +16,7 @@ termux_pkg_auto_update() {
 	tag="$(termux_github_api_get_tag "${TERMUX_PKG_SRCURL}")"
 	# check if this is not a c release:
 	if grep -qP "^cpp-${TERMUX_PKG_UPDATE_VERSION_REGEXP}\$" <<<"$tag"; then
-		pkg_dir=$(dirname "$0") termux_pkg_upgrade_version "$tag"
+		termux_pkg_upgrade_version "$tag"
 	else
 		echo "WARNING: Skipping auto-update: Not a cpp release($tag)"
 	fi

packages/libmsgpack/build.sh

@@ -21,7 +21,7 @@ termux_pkg_auto_update() {
 	tag="$(termux_github_api_get_tag "${TERMUX_PKG_SRCURL}")"
 	# check if this is not a c++ release:
 	if grep -qP "^c-${TERMUX_PKG_UPDATE_VERSION_REGEXP}\$" <<<"$tag"; then
-		pkg_dir=$(dirname "$0") termux_pkg_upgrade_version "$tag"
+		termux_pkg_upgrade_version "$tag"
 	else
 		echo "WARNING: Skipping auto-update: Not a C release($tag)"
 	fi

packages/neovim-nightly/build.sh

@@ -63,7 +63,7 @@ termux_pkg_auto_update() {
 
 	# since we are using a nightly build, therefore no need to check for version increment/decrement.
 	if [ "${TERMUX_PKG_VERSION}" != "${remote_nvim_version}" ]; then
-		pkg_dir=$(dirname "$0") termux_pkg_upgrade_version "${remote_nvim_version}" --skip-version-check
+		termux_pkg_upgrade_version "${remote_nvim_version}" --skip-version-check
 	else
 		echo "INFO: No update available."
 	fi

scripts/bin/update-packages

@@ -74,6 +74,8 @@ TERMUX_SCRIPTDIR="$(realpath "$(dirname "$0")/../..")" # Script directory.
 _update() {
 	export TERMUX_PKG_NAME
 	TERMUX_PKG_NAME="$(basename "$1")"
+	export TERMUX_PKG_BUILDER_DIR
+	TERMUX_PKG_BUILDER_DIR="$(realpath "$1")" # Directory containing build.sh.
 	# Avoid:
 	# - ending on errors such as $(which prog), where prog is not installed.
 	# - error on unbound variable.