Re: NOTICE for all package maintainers with faulty post-install scripts
On Thu, Aug 12, 2010 at 10:35:12AM -0400, Andrew Schulman wrote: >Let me be sure first that I understand the new functionality. By "fail" we >mean exiting with a non-zero status, correct? Yes. On Windows and on Unix a "failing" program means a program which exits with a non-zero status. For more details read the error reports in the Cygwin mailing list. If your package is failing it will be reported there. It may not have your package name in the subject, though, since several packages may be showing up in the dialog box. In theory my original message shouldn't even be needed but I'm not seeing a lot of responses from affected package maintainers on this issue so I wanted to make sure that it was understood that this needs to be addressed. cgf
Re: NOTICE for all package maintainers with faulty post-install scripts
Am 12.08.2010 16:35, schrieb Andrew Schulman: >> On Thu, Aug 12, 2010 at 09:56:49AM -0400, Andrew Schulman wrote: >> >> Thanks to Jon Turney's recent patch we've discovered that many >> >> post-install packages were previously failing silently. >> > >> >Failing silently... so what is the preferred protocol in case a >> >post-install script fails? Emit a message to stderr, which will be caught >> >and shown to the user? >> >> There is apparently a disconnect here. setup.exe now lets you know if a >> script fails. Scripts are not supposed to fail. Some scripts are >> routinely failing and should be fixed. >> >> If your script fails for a valid reason then of course exiting with a >> non-zero status is the way to go. That is what the new dialog box was >> intended to catch. >> >> If one of your scripts does fail then you should work out why with the >> affected user and take steps to make sure that it doesn't fail. > > Let me be sure first that I understand the new functionality. By "fail" we > mean exiting with a non-zero status, correct? Either that, or (hopefully) exit with a signal. > So when a postinstall or > preremove script exits non-zero, the user will be alerted of that fact? There's an error popup, but I don't know which details it reports other than pointing to setup.log.full or thereabouts. > And maybe output to stderr and/or stdout provided, in the hope that it will > help to diagnose the problem? > > I may just be confused by your phrase "failing silently". I'm just trying "failing silently" means that it was logged to some file but not alerted through the GUI, so that many users were unaware that the postinstall script had failed somehow. > to figure out how if at all I need to adjust my postinstall/preremove > scripts to check for non-zero exit statuses and try to provide useful > output about them. Most of those scripts are short, but some contain > multiple commands, any of which could fail for any number of reasons that > are hard to predict. Once a problem is well-known I can add code to check > for it and provide a useful message, but until then, either silence or a > possibly not very enlightening error message is going to be the usual mode > of failure. My primary concern is that packagers don't just write ":", "true", or "exit 0" at the end of their postinstall scripts to mask/hide the failure. My secondary concern is general quality of shell scripts (this is not relating to Cygwin postinstall scripts, which I've never looked at). Few people seem to be capable of writing solid shell scripts, because many people often just copy & paste snippets from Google without understanding the details. Shell scripts are a nuisance to some, and proper training material is hard to find on the web (there's a truckload of mediocre and incomplete stuff though), and so I often see unquoted variable expansions (that break on blanks in filenames already or empty variables), people treating (a) "foo && bar" and (b) "if foo ; then bar ; fi" as synonymous (abusively!) to accomodate their convenience, when in fact the exit semantics are different; "if" eats failures of its immediate condition command, whereas "foo && " will emit the failure status. Note that some older shell implementations (including older Almqvist and BSD shells) got some of these semantics wrong (meaning violating POSIX). -- Matthias Andree
Re: NOTICE for all package maintainers with faulty post-install scripts
> On Thu, Aug 12, 2010 at 09:56:49AM -0400, Andrew Schulman wrote: > >> Thanks to Jon Turney's recent patch we've discovered that many > >> post-install packages were previously failing silently. > > > >Failing silently... so what is the preferred protocol in case a > >post-install script fails? Emit a message to stderr, which will be caught > >and shown to the user? > > There is apparently a disconnect here. setup.exe now lets you know if a > script fails. Scripts are not supposed to fail. Some scripts are > routinely failing and should be fixed. > > If your script fails for a valid reason then of course exiting with a > non-zero status is the way to go. That is what the new dialog box was > intended to catch. > > If one of your scripts does fail then you should work out why with the > affected user and take steps to make sure that it doesn't fail. Let me be sure first that I understand the new functionality. By "fail" we mean exiting with a non-zero status, correct? So when a postinstall or preremove script exits non-zero, the user will be alerted of that fact? And maybe output to stderr and/or stdout provided, in the hope that it will help to diagnose the problem? I may just be confused by your phrase "failing silently". I'm just trying to figure out how if at all I need to adjust my postinstall/preremove scripts to check for non-zero exit statuses and try to provide useful output about them. Most of those scripts are short, but some contain multiple commands, any of which could fail for any number of reasons that are hard to predict. Once a problem is well-known I can add code to check for it and provide a useful message, but until then, either silence or a possibly not very enlightening error message is going to be the usual mode of failure. Anyway, I agreed that failure shouldn't happen routinely, it's good that failures are now going to be brought to our attention, and packagers should fix those problems when they get reported, which I guess was your main point. Andrew.
Re: NOTICE for all package maintainers with faulty post-install scripts
On Thu, Aug 12, 2010 at 04:19:44PM +0200, Matthias Andree wrote: >Am 12.08.2010 01:15, schrieb Christopher Faylor: >>Thanks to Jon Turney's recent patch we've discovered that many >>post-install packages were previously failing silently. Now we know >>exactly which packages are failing because people are reporting them to >>the cygwin list. >> >>These need to be fixed and I implore you to make it a priority. >>Otherwise we're doing a disservice to our user community. >> >>I know we all lack tuits but I really hope that all of the affected >>packages will take time to fix their problems. Just look at the cygwin >>mailing list (which you're all monitoring anyway) for errors and, if >>your package has an error, consider rolling a -N+1 release with a fix. > >Oh, and please, no "add 'exit 0'" nonsense at the end of scripts, as >I've just seen fly by on cygwin@ [1] - this will make matters worse and >hide the now-noisy-and-formerly-silent failures more deeply in the >system so that they're even harder to find, report, and fix. > >I also urgently seek those with upload privileges to refuse such >"fixes". Yes. What he said. Silently "succeeding" is not a fix for this problem. cgf
Re: NOTICE for all package maintainers with faulty post-install scripts
Am 12.08.2010 01:15, schrieb Christopher Faylor: > Thanks to Jon Turney's recent patch we've discovered that many > post-install packages were previously failing silently. Now we know > exactly which packages are failing because people are reporting them > to the cygwin list. > > These need to be fixed and I implore you to make it a priority. > Otherwise we're doing a disservice to our user community. > > I know we all lack tuits but I really hope that all of the affected > packages will take time to fix their problems. Just look at the cygwin > mailing list (which you're all monitoring anyway) for errors and, if > your package has an error, consider rolling a -N+1 release with a fix. Oh, and please, no "add 'exit 0'" nonsense at the end of scripts, as I've just seen fly by on cygwin@ [1] - this will make matters worse and hide the now-noisy-and-formerly-silent failures more deeply in the system so that they're even harder to find, report, and fix. I also urgently seek those with upload privileges to refuse such "fixes". _ [1] http://www.cygwin.com/ml/cygwin/2010-08/msg00291.html and references -- Matthias Andree
Re: NOTICE for all package maintainers with faulty post-install scripts
On Thu, Aug 12, 2010 at 09:56:49AM -0400, Andrew Schulman wrote: >> Thanks to Jon Turney's recent patch we've discovered that many >> post-install packages were previously failing silently. > >Failing silently... so what is the preferred protocol in case a >post-install script fails? Emit a message to stderr, which will be caught >and shown to the user? There is apparently a disconnect here. setup.exe now lets you know if a script fails. Scripts are not supposed to fail. Some scripts are routinely failing and should be fixed. If your script fails for a valid reason then of course exiting with a non-zero status is the way to go. That is what the new dialog box was intended to catch. If one of your scripts does fail then you should work out why with the affected user and take steps to make sure that it doesn't fail. cgf
Re: NOTICE for all package maintainers with faulty post-install scripts
> Thanks to Jon Turney's recent patch we've discovered that many > post-install packages were previously failing silently. Failing silently... so what is the preferred protocol in case a post-install script fails? Emit a message to stderr, which will be caught and shown to the user? If a post-install script fails in an ignorable way, then does this mean it's not acceptable to allow the script to exit with a non-zero status? That is, we have to either exit 0, or else exit non-zero and emit a useful message? If a post-install script succeeds (and exits with status 0) but still emits text to stderr or even stdout, will that text also be caught and shown to the user? Do the answers to all of the above also apply to preremove scripts? Sorry if some of this has already been discussed. I haven't followed all of the discussion of this new feature. Thanks, Andrew.
NOTICE for all package maintainers with faulty post-install scripts
Thanks to Jon Turney's recent patch we've discovered that many post-install packages were previously failing silently. Now we know exactly which packages are failing because people are reporting them to the cygwin list. These need to be fixed and I implore you to make it a priority. Otherwise we're doing a disservice to our user community. I know we all lack tuits but I really hope that all of the affected packages will take time to fix their problems. Just look at the cygwin mailing list (which you're all monitoring anyway) for errors and, if your package has an error, consider rolling a -N+1 release with a fix. Thanks. cgf
