1291843 - Windows build configure fails: UnicodeDecodeError: 'charmap' codec can't decode byte 0x81 in position 62: character maps to <undefined>

Status: RESOLVED WORKSFORME

(Firefox Build System :: General, defect)

Description

[Jan Henning [:JanH]]

Previous builds are broken because of bug 1289291, after bug 1289679 the error is then replaced by the UnicodeDecodeError mentioned in the title.
My system:
Windows 7 64-bit, VS2015u2, SDK 10.0.10586.0 and I fear that the fact both Windows and VS are the German language editions might have something to do with it

Comment 1

[Mike Hommey [:glandium]]

Please attach a full log.

Comment 2

[Jan Henning [:JanH]]

Attachment: build.log

There you are. My mozconfig is just a simple

> ac_add_options --enable-debug
> ac_add_options --disable-optimize
> 
> mk_add_options MOZ_OBJDIR=./objdir-firefox

Comment 3

[Mike Hommey [:glandium]]

Can you give the output for the following command:
./mach python -c 'from mozbuild.configure.util import getpreferredencoding; print getpreferredencoding()'

Comment 4

[Jan Henning [:JanH]]

Will do when I get back home. On second thoughts, it wasn't neccessarily bug 1289679 itself that introduced this problem, in fact if could have been anything inbetween bug 1289291 and 1289679 (approximately this range: https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=78dd94ba93c7&tochange=db3ed1fdbbea) because this failure would have been masked by the failure to detect the Windows 10 SDK.

Comment 5

[Jan Henning [:JanH]]

That command returns cp1252.

Comment 7

[Jan Henning [:JanH]]

I wanted to poke around something on desktop and ran into this again.

Comment 8

[Jan Henning [:JanH]]

It seems like for some reason the Visual Studio compiler is using the the *DOS* Western Europe codepage here or something like that...

0x81 corresponds to an "ü", which doesn't sound unreasonable and passing 'cp850' as the encoding to use here [1] makes things works again, although it is of course not applicable as a generic fix (and when redirecting the build output to a log file, the "ü" appears somewhat mangled there).

[1] https://dxr.mozilla.org/mozilla-central/rev/0eef1d5a39366059677c6d7944cfe8a97265a011/python/mozbuild/mozbuild/configure/util.py#204

Comment 9

[Jan Henning [:JanH]]

I got rid of my local workaround quite a while ago, possibly it was the switch to clang-cl (potentially in combination with sccache) that fixed it?