Re: WebKitGTK-2.52.5

On Wed, 2026-08-19 at 20:56 -0500, Bruce Dubbs wrote:
> On 8/19/26 6:51 PM, Bruce Dubbs wrote:
> > On 8/19/26 5:46 PM, Zeckma ([email protected] via blfs-dev
> > Mailing List) wrote:
> > > On 8/19/26 15:58, Bruce Dubbs ([email protected] via blfs-dev
> > > Mailing List) wrote:
> > >  > I had a bit of a problem with building WebKitGTK-2.52.5 on a
> > > 13.1
> > >  > system. I'm using a system with 28 cores.  When I tried to
> > > build
> > >  > WebKitGTK-2.52.5 using all 28 cores, it failed to build.  The
> > >  > message was something about a file that was not complete.  I
> > >  > tried twice and it failed at the same point.  I then tried at
> > > -j8
> > >  > and the build was successful.
> > > 
> > > I suspect that this is a result of incomplete dependency
> > > information.
> > > I've run into this with samurai, a reimplementation of the Ninja
> > > build system, which runs into this issue a lot. But it isn't
> > > really
> > > the fault of samurai.
> > > 
> > > -j1 or a small amount of threads will conveniently get around the
> > > issue of missing dependency information, but if a large or
> > > larger amount of threads are used, a rule or target simply won't
> > > wait for another to complete, and bails. With dependency
> > > information,
> > > the rule will then wait for the dependent rule/target to complete
> > > before running.
> > > 
> > > With how large WebKitGTK is, I imagine this is such a case.
> > > Usually, this seems to happen more with Meson, and I haven't seen
> > > a CMake case yet. But typically this is very fixable if you know
> > > what depedency information is missing and what needs it.
> > > 
> > > Thus, the solution would be to fix the code. Another may be to
> > > use
> > > Make instead of Ninja and see if that helps, but Ninja due to its
> > > methodology happens to avoid most stuff like this except for lots
> > > of targets that big projects like WebKitGTK need. So if Make
> > > doesn't
> > > bear fruit or it's really inconsistent, either an admon (note,
> > > important, etc.) or fixing the build system would be my two
> > > recommendations.
> > > 
> > > What was your build error? May give a good clue as to what the
> > > target
> > > is that is missing the dependency information...
> > 
> > Right, I figured it is a dependency issue with a generated file.
> > 
> > I've overwritten the log.  I suppose I can run it again without the
> > install. I'm 
> > still trying to update to Qt-6.11.2 so it will be a while until I
> > can do that.
> > 
> > BYW, I noticed that qt6 patch has been incorporated into 6.11.2,
> > but qtopcua still 
> > breaks.
> 
> I ran it again and saved the output.
> 
> [8461/9424] Building CXX object 
> Source/WebCore/CMakeFiles/WebCore.dir/__/__/WebCore/DerivedSources/un
> ified-sources/UnifiedSource-be65d27a-7.cpp.o
> FAILED: [code=1] 
> Source/WebCore/CMakeFiles/WebCore.dir/__/__/WebCore/DerivedSources/un
> ified-sources/UnifiedSource-be65d27a-7.cpp.o 
> 
> 
> That was on line 57222 of the output.  Around line 57621 is the
> message:
> 
> Assembler messages:
> {standard input}:93901: Warning: end of file not at end of a line;
> newline inserted
> c++: fatal error: Killed signal terminated program cc1plus
> compilation terminated.
> 
> I was monitoring CPU and memory while it was building.  I saw 98%
> memory usage (I 
> have 64G ram) and load values up to 28.  It's possible I ran out of
> memory, but I do 
> have 8G swap.
> 

I'm almost sure it is an OOM problem. On a 16GB virtual machine, I need
to pass -j3. -j4 and higher fails. Those "UnifiedSource" files may need
more than 3GB for compilation. So at -j4, I may need ore than 12GB,
which together with memory used by the system makes it more than 16GB. 

I think with 64GB, allowing around 4GB for the system, you shouldn't
run more than 20 threads, or maybe a little less. Note that swapping
will slow down the system a lot, don't rely on it!

We already say in "notes on building software":
---
Some compilations with g++ may consume up to 2.5 GB
of memory, so to be safe, you should restrict the number of jobs
to (Total Memory in GB)/2.5, at least for big packages such as LLVM,
WebKitGtk, QtWebEngine, or libreoffice.
---
I think now 2.5 should be replaced with 3. Also, I've never seen a
problem in libreoffice or llvm...

Pierre

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