Re: [PATCH 1/5] rpm.eclass: rework app-arch/rpm support into pre-inherit variable

On 22/04/2026 16:23, Eli Schwartz wrote:
> app-arch/rpm supports various compression types, but usually via USE
> flags. We need ugly strings|grep to see which one is needed. rpm2targz
> dynamically detects `@system` set tools which is why it has worked
> forever.
> 
> To solve this we add RPM_COMPRESS_TYPE="" before inheriting the eclass,
> which controls if app-arch/rpm is used. While testing this it also turns
> out legacy lzma is not supported by rpm2targz at all, so exclude it in
> such cases.
> 
> The eclass now has effectively a "mandatory for proper support" eclass
> pre-inherit variable which nothing ever set before. Emit an eqawarn if
> it is being "held wrong", to encourage people to set this variable.
> 
> Closes: https://bugs.gentoo.org/973073
> Closes: https://bugs.gentoo.org/971578
> Bug: https://bugs.gentoo.org/971600
> Signed-off-by: Eli Schwartz <[email protected]>
> ---
>   eclass/rpm.eclass | 97 ++++++++++++++++++++++++++++++++++++++++++-----
>   1 file changed, 87 insertions(+), 10 deletions(-)
> 
> diff --git a/eclass/rpm.eclass b/eclass/rpm.eclass
> index 3b7f9e64355b..8ee248703aa1 100644
> --- a/eclass/rpm.eclass
> +++ b/eclass/rpm.eclass
> @@ -17,12 +17,59 @@ _RPM_ECLASS=1
>   
>   inherit estack
>   
> -BDEPEND="
> -	|| (
> -		app-arch/rpm2targz
> -		>=app-arch/rpm-4.19.0
> -	)
> -"
> +# @ECLASS_VARIABLE: RPM_COMPRESS_TYPE
> +# @PRE_INHERIT
> +# @DEFAULT_UNSET
> +# @DESCRIPTION:
> +# Comma-separated list of app-arch/rpm compression formats. If set,
> +# app-arch/rpm will be allowed as a BDEPEND to unpack distfiles. Supported
> +# types:
> +#
> +# - none (rpm is supported but distfile is uncompressed or builtin zlib)
> +#
> +# - bzip2 (.bz2)
> +#
> +# - lzma (deprecated pre-xz iteration of the lzma SDK. rpm2targz doesn't
> +#   support it)
> +#
> +# - xz (.xz)
> +#
> +# - zstd (.zst)
> +#
> +# - "" (empty -- the ebuild hasn't been updated to resolve deprecations)
> +
> +_rpm_set_globals() {
> +	local rpmdep= rpm2tar="true" t= types=()
> +	IFS=, declare -a 'types=(${RPM_COMPRESS_TYPE})'
> +
> +	if [[ ${RPM_COMPRESS_TYPE} = none ]]; then
> +		rpmdep=""
> +	elif [[ "${#types[@]}" -gt 0 ]]; then
> +		for t in "${types[@]}"; do
> +			case ${t} in
> +				bzip2|zstd) rpmdep+="${t}," ;;
> +				lzma) rpmdep+="${t},"; rpm2tar="false" ;;
> +				xz) rpmdep+="lzma," ;;
> +				none) die "RPM_COMPRESS_TYPE=none must be used alone" ;;
> +				*) die "invalid RPM_COMPRESS_TYPE: ${RPM_COMPRESS_TYPE} (found: ${t})" ;;
> +			esac
> +		done
> +		rpmdep="[${rpmdep%,}]"
> +	fi
> +
> +	if [[ ${rpm2targz} = true ]]; then

Spotted a typo here, the name of the variable as initialized above is 
"rpm2tar" not "rpm2targz".

> +		BDEPEND="
> +			|| (
> +				app-arch/rpm2targz
> +				app-arch/rpm${rpmdep}
> +			)
> +		"
> +	else
> +		BDEPEND="app-arch/rpm${rpmdep}"
> +	fi
> +}
> +_rpm_set_globals
> +unset -f _rpm_set_globals
>   
>   # @FUNCTION: rpm_unpack
>   # @USAGE: <rpms>
> @@ -30,7 +77,10 @@ BDEPEND="
>   # Unpack the contents of the specified rpms like the unpack() function.
>   rpm_unpack() {
>   	[[ $# -eq 0 ]] && set -- ${A}
> -	local a
> +	local a noticed=()
> +
> +	IFS=, declare -a 'types=(${RPM_COMPRESS_TYPE})'
> +
>   	for a in "$@" ; do
>   		echo ">>> Unpacking ${a} to ${PWD}"
>   		if [[ ${a} == ./* ]] ; then
> @@ -43,11 +93,38 @@ rpm_unpack() {
>   			a="${DISTDIR}/${a}"
>   		fi
>   
> -		if command -v rpm2tar >/dev/null; then
> -			local extracttool=(rpm2tar -O)
> +		local payload= usedep=""
> +		if [[ ${a} = *.src.rpm ]]; then
> +			payload=none
>   		else
> -			# app-arch/rpm fallback
> +			payload=$(strings "${a}" | grep -o 'PayloadIs[a-zA-Z]*'; pipestatus || die "failed to grep rpm payload")
> +		fi
> +
> +		case ${payload} in
> +			"") payload=none;; # gzip/uncompressed
> +			PayloadIsBzip) payload=bzip2 usedep="[bzip2]";;
> +			PayloadIsXz) payload=xz usedep="[lzma]";;
> +			PayloadIsLzma) payload=lzma usedep="[lzma]";;
> +			PayloadIsZstd) payload=zstd usedep="[zstd]";;
> +		esac
> +
> +		local use_rpm=
> +		if [[ ${RPM_COMPRESS_TYPE} = *${payload}* ||
> +			  ( ${payload} = none && ${RPM_COMPRESS_TYPE} ) ]]; then
> +			use_rpm=true
> +		elif ! has "${payload}" "${noticed[@]}"; then
> +			eqawarn "QA Notice: rpm_unpack called without supporting app-arch/rpm."
> +			eqawarn "\${RPM_COMPRESS_TYPE} should include '${payload}'."
> +			noticed+=("${payload}")
> +		fi
> +
> +		if [[ ${use_rpm} = true ]] && has_version -b "app-arch/rpm${usedep}"; then
> +			# prefer it if correct USE is in BDEPEND and installed
>   			local extracttool=(rpm2archive -n)
> +		elif [[ ${payload} = lzma ]]; then
> +			die "rpm_unpack called with legacy lzma compression that rpm2targz doesn't support"
> +		else
> +			local extracttool=(rpm2tar -O)
>   		fi
>   
>   		"${extracttool[@]}" "${a}" | tar xf -