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Review their scripts and packages whether they use ''time' in non-POSIX mode and parse times's output. If they are affected, they should add ''-q'' option to the ''time'' command, or adjust their code do deal with the new first line. | Review their scripts and packages whether they use ''time' in non-POSIX mode and parse times's output. If they are affected, they should add ''-q'' option to the ''time'' command, or adjust their code do deal with the new first line. | ||
* FIXME: Release engineering: [https://pagure.io/releng/ | * FIXME: Release engineering: [https://pagure.io/releng/issue/7153] | ||
** [[Fedora_Program_Management/ReleaseBlocking/Fedora{{FedoraVersionNumber|next}}|List of deliverables]]: Anything that contains ''time'' package. | ** [[Fedora_Program_Management/ReleaseBlocking/Fedora{{FedoraVersionNumber|next}}|List of deliverables]]: Anything that contains ''time'' package. | ||
* Policies and guidelines: No change is needed. | * Policies and guidelines: No change is needed. |
Revision as of 17:57, 9 November 2017
Changes/time-1.8
Summary
A new time tool version 1.8 has changed output format.
Owner
- Name: Petr Písař
- Email: <ppisar@redhat.com>
- Release notes owner:
Current status
- Targeted release: Fedora 28
- Last updated: 2017-11-09
- Tracker bug: <will be assigned by the Wrangler>
Detailed Description
After many years a new 1.8 version of time tool was released. This version brings some noticeable changes:
- License changed from (GPLv2+) to (GPLv3+ and GFDL).
- Additional exit codes are used to report measured command failures and failures to execute the command.
- A measured command failure is reported by default. See the first line in this output:
$ time /usr/bin/false Command exited with non-zero status 1 0.00user 0.00system 0:00.00elapsed 100%CPU (0avgtext+0avgdata 1196maxresident)k 0inputs+0outputs (0major+55minor)pagefaults 0swaps
In previous Fedora versions, the first line was printed only if -v option was specified. This is not true anymore and the line is printed by default. You can disable it with a new -q option:
$ time -q /usr/bin/false 0.00user 0.00system 0:00.00elapsed 100%CPU (0avgtext+0avgdata 1268maxresident)k 0inputs+0outputs (0major+55minor)pagefaults 0swaps
Because this violated POSIX mode, Fedora changed time-1.8 not to print the first line when invoked with -p option and upstream accepted the change so that future time versions will behave like Fedora. For Fedora users, there is no change in POSIX mode output:
$ time -p /usr/bin/false real 0.00 user 0.00 sys 0.00
If you use time tool in your script without the -p option, then either adjust your script to expect different output, or add -q option. Be ware of portability across distributions using different time versions.
Benefit to Fedora
Fedora provides up-to-date time tool that conforms to POSIX. Usage of the POSIX mode is improves portability.
Scope
- Proposal owners:
The time package will be upgraded and patched to preserve output format in POSIX mode.
- Other developers:
Review their scripts and packages whether they use time' in non-POSIX mode and parse times's output. If they are affected, they should add -q option to the time command, or adjust their code do deal with the new first line.
- FIXME: Release engineering: [1]
- List of deliverables: Anything that contains time package.
- Policies and guidelines: No change is needed.
- Trademark approval: No approval is needed.
Upgrade/compatibility impact
Scripts that parses time output could stop working. Scripts that invokes time with -p option are not affected.
How To Test
Install time package and check that:
time -p COMMAND
behaves as in previous Fedoras.time COMMAND
prints a new leading line, if the COMMAND failed.
Install a package that uses time tool and check it still works as expected.
User Experience
The time tool reports a command failure on the first line of standard error output. The report can be disabled with -q option.
Dependencies
To this date, there are only 6 packages that require time package.
- akmods
- kcbench
- nfsometer
- ohc
- redhat-lsb
- winetricks
Contingency Plan
- Contingency mechanism: The default command failure reporting will be disabled or the upgrade will be reverted to 1.7 version.
- Contingency deadline: Anytime.
- Blocks release? No.
- Blocks product? No.
Documentation
- Upstream announcement about intention to release 1.8 version
- Upstream time 1.8 release notes
- Upstream bug report about broken POSIX output
- Announcement on Fedora devel mainling list
Release Notes
time tool 1.8 has changed default output format. If the measured command fails, it reports about it on the first line of time's standard error output. This report can be suppressed by using -q option. The POSIX mode (-p option) is unchanged. Users are advised to review their scripts for make sure they can parse the new time output.