Re: [gentoo-portage-dev] [PATCH v3] install-qa-check: New QA check/cleanup for empty directories

[Zac Medico]

On 01/30/2018 10:18 AM, Zac Medico wrote:
> On 01/29/2018 11:23 PM, Michał Górny wrote:
>> Warn about empty directories installed to /var in install-qa-check phase
>> (that were not "filled" using keepdir), to help developers stop relying
>> upon Portage preserving them. Those directories are rather unlikely to
>> be false positives.
>>
>> Furthermore, remove all the empty directories if FEATURES=strict-keepdir
>> is used to catch even more problems (intended for developers). Here
>> warnings are not really suitable since there will be a high number
>> of false positives.
>>
>> The PMS specifies the behavior upon merging empty directories
>> as undefined, and specifically prohibits ebuilds from attempting
>> to install empty directories. However, ebuilds occasionally still fall
>> into the trap of relying on 'dodir' preserving the directory. Make
>> the Portage behavior more strict in order to prevent that.
>> ---
>>  bin/install-qa-check.d/95empty-dirs | 42 +++++++++++++++++++++++++++++++++++++
>>  man/make.conf.5                     |  4 ++++
>>  pym/portage/const.py                |  1 +
>>  3 files changed, 47 insertions(+)
>>  create mode 100644 bin/install-qa-check.d/95empty-dirs
>>
>> diff --git a/bin/install-qa-check.d/95empty-dirs b/bin/install-qa-check.d/95empty-dirs
>> new file mode 100644
>> index 000000000..0d06b278d
>> --- /dev/null
>> +++ b/bin/install-qa-check.d/95empty-dirs
>> @@ -0,0 +1,42 @@
>> +# Warn about and/or remove empty directories installed by ebuild.
>> +
>> +# Rationale: PMS prohibits ebuilds from installing empty directories.
>> +# Cleaning them up from the installation image provides an easy way
>> +# to make sure that ebuilds are not relying on it while making it easy
>> +# for users to override this if they need to.
>> +#
>> +# The ebuilds that need to preserve empty directories should use keepdir
>> +# as documented e.g.:
>> +# https://devmanual.gentoo.org/function-reference/install-functions/index.html
>> +#
>> +# For now, we emit QA warnings for empty directories in /var.
>> +# Additionally, if FEATURES=strict-keepdir is enabled we explicitly
>> +# remove *all* empty directories to trigger breakage.
>> +
>> +find_empty_dirs() {
>> +	local warn_dirs=()
>> +	local d striparg=
>> +
>> +	[[ ${FEATURES} == *strict-keepdir* ]] && striparg=-delete
>> +
>> +	while IFS= read -r -d $'\0' d; do
>> +		[[ ${d} == ${ED%/}/var/* ]] && warn_dirs+=( "${d}" )
>> +	done < <(find "${ED}" -depth -mindepth 1 -type d -empty -print0 ${striparg} | sort -z)
>
> Are you sure that this sort call is guaranteed to produce the correct
> order? Comparison of '-' characters with '/' characters can lead to odd
> results like this:
>
> $ printf 'foo/bar\nfoo-bar/baz\nfoo/bar/baz\n' | sort
> foo/bar
> foo-bar/baz
> foo/bar/baz

The sort is only for display purposes, maybe use LC_ALL=C for locale
independence?
-- 
Thanks,
Zac