On 12/4/19 8:24 AM, Wilco Dijkstra wrote: > Hi Jeff, > >>> I've noticed quite significant package failures caused by the revision. >>> Would you please consider documenting this change in porting_to.html >>> (and in changes.html) for GCC 10 release? >> >> I'm not in the office right now, but figured I'd chime in. I'd estimate >> 400-500 packages are failing in Fedora because of this change. I'll >> have a hard number Monday. >> >> It's significant enough that I'm not sure how we're going to get them >> all fixed. > > So what normally happens with the numerous new warnings/errors in GCC > releases? I suppose that could cause package failures too. Would it be > feasible > to override the options for any failing packages? Usually we're talking about a few dozen packages that are tripped by any particular issue. The -fno-common issue is a full order of magnitude larger. My builds show ~450 failures due to this issue.
We're investigating different approaches that don't just involve reverting the patch or reverting for Fedora. Those just kick the can down the road with no real progress and we're in the same position next year. The approach that seems most feasible would be to have an opt-out mechanism. That would keep -fno-common as the default but provide a mechanism for a package to opt-out. Of the ~450 packages affected I'd estimate that even with the opt-out mechanism we're still going to have to fix ~100 packages immediately because they don't honor the flags injection mechanisms which the opt-out approach relies upon. I'm going to do some testing today/tomorrow to see how many affected packages don't honor the flags injection mechanisms we use. If indeed it's ~100 packages that don't honor the flags injection, then we're looking at adding 350 markers to opt-out plus ~100 real fixes/workarounds. That's still a lot of mindless work, but probably in the realm of possible. I will highlight that having the tester has proven hugely valuable here. If we'd found out about this later in the process we'd probably be looking seriously at reversion. jeff
