Add "devel" variant from Chet's "devel" branch

Chet updates a "devel" branch in https://git.savannah.gnu.org/cgit/bash.git roughly every seven days, which is a very reasonable cadence and worth publishing an image for.

Author: tianon

.travis.yml

@@ -2,6 +2,7 @@ language: bash
 services: docker
 
 env:
+  - VERSION=devel
   - VERSION=5.0
   - VERSION=4.4
   - VERSION=4.3

devel/Dockerfile

@@ -0,0 +1,83 @@
+FROM alpine:3.10
+
+# https://git.savannah.gnu.org/cgit/bash.git/commit/?h=devel
+ENV _BASH_COMMIT ea578790a910fcd394930de7a1933a9ee24f9119
+# prefixed with "_" since "$BASH..." have meaning in Bash parlance
+
+RUN set -eux; \
+	\
+	apk add --no-cache --virtual .build-deps \
+		bison \
+		coreutils \
+		dpkg-dev dpkg \
+		gcc \
+		libc-dev \
+		make \
+		ncurses-dev \
+		tar \
+	; \
+	\
+	wget -O bash.tar.gz "https://git.savannah.gnu.org/cgit/bash.git/snapshot/bash-$_BASH_COMMIT.tar.gz"; \
+	\
+	mkdir -p /usr/src/bash; \
+	tar \
+		--extract \
+		--file=bash.tar.gz \
+		--strip-components=1 \
+		--directory=/usr/src/bash \
+	; \
+	rm bash.tar.gz; \
+	\
+	if [ -d bash-patches ]; then \
+		for p in bash-patches/*; do \
+			patch \
+				--directory=/usr/src/bash \
+				--input="$(readlink -f "$p")" \
+				--strip=0 \
+			; \
+			rm "$p"; \
+		done; \
+		rmdir bash-patches; \
+	fi; \
+	\
+	cd /usr/src/bash; \
+	gnuArch="$(dpkg-architecture --query DEB_BUILD_GNU_TYPE)"; \
+	./configure \
+		--build="$gnuArch" \
+		--enable-readline \
+		--with-curses \
+# musl does not implement brk/sbrk (they simply return -ENOMEM)
+#   bash: xmalloc: locale.c:81: cannot allocate 18 bytes (0 bytes allocated)
+		--without-bash-malloc \
+	|| { \
+		cat >&2 config.log; \
+		false; \
+	}; \
+	make -j "$(nproc)"; \
+	make install; \
+	cd /; \
+	rm -r /usr/src/bash; \
+	\
+# delete a few installed bits for smaller image size
+	rm -r \
+		/usr/local/share/doc/bash/*.html \
+		/usr/local/share/info \
+#		/usr/local/share/locale \
+		/usr/local/share/man \
+	; \
+	\
+	runDeps="$( \
+		scanelf --needed --nobanner --format '%n#p' --recursive /usr/local \
+			| tr ',' '\n' \
+			| sort -u \
+			| awk 'system("[ -e /usr/local/lib/" $1 " ]") == 0 { next } { print "so:" $1 }' \
+	)"; \
+	apk add --no-cache --virtual .bash-rundeps $runDeps; \
+	apk del .build-deps; \
+	\
+	[ "$(which bash)" = '/usr/local/bin/bash' ]; \
+	bash --version
+
+COPY docker-entrypoint.sh /usr/local/bin/
+ENTRYPOINT ["docker-entrypoint.sh"]
+CMD ["bash"]

devel/docker-entrypoint.sh

@@ -0,0 +1,11 @@
+#!/usr/bin/env bash
+set -Eeuo pipefail
+
+# first arg is `-f` or `--some-option`
+# or there are no args
+if [ "$#" -eq 0 ] || [ "${1#-}" != "$1" ]; then
+	# docker run bash -c 'echo hi'
+	exec bash "$@"
+fi
+
+exec "$@"

update.sh

@@ -24,6 +24,19 @@ for version in "${versions[@]}"; do
 		rcGrepV=
 	fi
 
+	if [ "$version" = 'devel' ]; then
+		commit="$(git ls-remote https://git.savannah.gnu.org/git/bash.git refs/heads/devel | cut -d$'\t' -f1)"
+		if [ -z "$commit" ]; then
+			echo >&2 "error: cannot determine commit for $version (from https://git.savannah.gnu.org/cgit/bash.git)"
+			exit 1
+		fi
+		echo "$version: $commit"
+		sed -ri -e 's/^(ENV _BASH_COMMIT) .*/\1 '"$commit"'/' "$version/Dockerfile"
+		cp -a docker-entrypoint.sh "$version/"
+		travisEnv='\n  - VERSION='"$version$travisEnv"
+		continue
+	fi
+
 	bashVersion="$rcVersion"
 
 	IFS=$'\n'
@@ -62,15 +75,15 @@ for version in "${versions[@]}"; do
 		bashVersion="$latestVersion" # "5.0-beta", "5.0-alpha", etc
 	fi
 
-	(
-		set -x
-		sed -ri '
-			s/^(ENV _BASH_VERSION) .*/\1 '"$bashVersion"'/;
-			s/^(ENV _BASH_PATCH_LEVEL) .*/\1 '"$patchLevel"'/;
-			s/^(ENV _BASH_LATEST_PATCH) .*/\1 '"$latestPatch"'/
-		' "$version/Dockerfile"
-		cp -a docker-entrypoint.sh "$version/"
-	)
+	echo "$version: $latestVersion"
+
+	sed -ri \
+		-e 's/^(ENV _BASH_VERSION) .*/\1 '"$bashVersion"'/' \
+		-e 's/^(ENV _BASH_PATCH_LEVEL) .*/\1 '"$patchLevel"'/' \
+		-e 's/^(ENV _BASH_LATEST_PATCH) .*/\1 '"$latestPatch"'/' \
+		"$version/Dockerfile"
+	cp -a docker-entrypoint.sh "$version/"
+
 	travisEnv='\n  - VERSION='"$version$travisEnv"
 done