install-build-deps.sh

#!/bin/bash
set -e

deb="$(mktemp --tmpdir build-deps-XXXXXXXXXX.deb)"
trap "rm -f '$deb'" EXIT

"$(dirname "$(readlink -f "$BASH_SOURCE")")/make-build-deps.sh" "$deb"
dpkg --unpack "$deb"
depsPackage="$(dpkg-deb -f "$deb" Package)"

if ! apt-get install -f "$@"; then
	dpkg --remove "$depsPackage"
	echo >&2 "error: failed to 'apt-get install -f'"
	exit 1
fi

if ! dpkg -s "$depsPackage" &> /dev/null; then
	echo >&2 "error: failed to install 'build-deps' package"
	exit 1
fi

make-build-deps.sh

#!/bin/bash
set -e

# https://sources.debian.net/src/devscripts/2.15.3/scripts/mk-build-deps.pl/
deb="$1"
if [ -z "$deb" ]; then
	echo >&2 "usage: $0 target-deb"
	echo >&2 "   ie: $0 /path/to/some/output.deb"
	exit 1
fi

read_control() {
	local field="$1"
	awk -F ': +' '
		$0 == "" { exit }
		/^#/ { next }
		/^ +/ && field != "" { value = value $0; next }
		field && field == "'"$field"'" {
			gsub(/(, *)+/, ", ", value);
			gsub(/^ +/, " ", value);
			gsub(/^,? |,? $/, "", value);
			print value;
			exit;
		}
		$2 != "" { field = $1; value = $2 }
	' debian/control
}

read_changelog() {
	local field="$1"
	if command -v dpkg-parsechangelog &> /dev/null; then
		dpkg-parsechangelog -S "$field"
	else
		f=
		case "$field" in
			Source) f=1 ;;
			Version) f=2 ;;
			*) echo >&2 "warning: unknown field $field"; return ;;
		esac
		local value="$(head -n1 debian/changelog | cut -d' ' -f"$f")"
		value="${value#(}"
		value="${value%)}"
		echo "$value"
	fi
}

package="$(read_control 'Source')"
version="$(read_control 'Version')"
if [ -z "$version" ]; then
	if [ -f debian/changelog -a "$(read_changelog 'Source')" = "$package" ]; then
		version="$(read_changelog 'Version')"
	else
		version='1.0'
	fi
fi

buildDepends="$(read_control 'Build-Depends'), $(read_control 'Build-Depends-Indep')"
buildDepends="${buildDepends%, }"
buildDepends="${buildDepends#, }"

buildConflicts="$(read_control 'Build-Conflicts'), $(read_control 'Build-Conflicts-Indep')"
buildConflicts="${buildConflicts%, }"
buildConflicts="${buildConflicts#, }"

arch='all'
if [[ "$buildDepends" =~ \[|\] ]]; then
	arch="$(dpkg-architecture -qDEB_HOST_ARCH)"
fi

tmpDir="$(mktemp -d)"
trap "rm -rf '$tmpDir'" EXIT

ourPackage="${package}-build-deps"

mkdir -p "$tmpDir/$ourPackage/DEBIAN"
{
	cat <<-EOF
		Architecture: $arch
		Depends: build-essential, $buildDepends
		Maintainer: N/A
		Package: $ourPackage
		Priority: optional
		Section: devel
		Standards-Version: 3.9.6
		Version: $version
	EOF
	[ -z "$buildConflicts" ] || echo "Conflicts: $buildConflicts"
	echo "Description: build-dependencies for $package"
	echo " Depencency package to build the '$package' package"
} | tee "$tmpDir/$ourPackage/DEBIAN/control"

echo

#deb="$tmpDir/$ourPackage.deb"
dpkg-deb --build "$tmpDir/$ourPackage" "$deb"

#dpkg-deb --info "$deb"
#dpkg-deb --contents "$deb"

# test it in debian:sid via Docker, just for kicks
#docker run -it --rm -v "$(readlink -f "$deb")":/temp.deb:ro debian:sid bash -c 'dpkg -i /temp.deb || { apt-get update && apt-get install -f; }'