[PATCH 1/1] cygwin: use CREATE_DEFAULT_ERROR_MODE in spawn

Jon Turney jon.turney@dronecode.org.uk
Tue Dec 8 14:43:53 GMT 2020

On 07/12/2020 09:43, Corinna Vinschen wrote:
> On Dec  4 10:35, Jeremy Drake via Cygwin-patches wrote:
>> On Fri, 4 Dec 2020, Corinna Vinschen via Cygwin-patches wrote:
>>> I'm not happy about a new CYGWIN option.
>>> Wouldn't it make sense, perhaps, to switch to CREATE_DEFAULT_ERROR_MODE
>>> for all non-Cygwin processes by default instead?

I agree.

Cygwin calls SetErrorMode(), so we need to use this flag to prevent that 
non-default behaviour being inherited by processes started with 

>> In fact, my first iteration was to set that flag unconditionally (relying
>> on the fact that SetErrorMode is called extremely early in Cygwin process
>> startup rather than only setting it for non-Cygwin processes), but I
>> received feedback that it would be better to put it behind an option:
>> https://github.com/msys2/msys2-runtime/pull/18#issuecomment-723683606

I don't really understand what that comment is saying.  If Git for 
Windows doesn't want the default SetErrorMode(), it should change it itself.

(The same executable not started by Cygwin will get the default error 
mode in any case).

> Jon, thoughts on that as GDB maintainer?

I don't think this actually interacts with gdb.

gdb either CreateProcess() with DEBUG_PROCESS (which presumably 
overrides that flag) or attaches to an existing process (possibly due to 
being configured as a JIT debugger).

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