Re: [PATCH v7 02/15] trace2: create new combined trace facility

> On Fri, Feb 22, 2019 at 02:25:01PM -0800, Jeff Hostetler via GitGitGadget wrote:
>> From: Jeff Hostetler <jeffhost@microsoft.com>
>>
>> * GIT_TR2_EVENT is a new structured format. It writes event data as a
>>   series of JSON records.
> 
> Please document these new environment variables in
> 'Documentation/git.txt', where the other environment variables,
> including GIT_TRACE_*, are already documented.

> While doing so, please note that the description about the possible
> values of these variables and of GIT_TRACE above is incomplete,
> because it's not just "1" or an absolute pathname.  Quoting the
> description of GIT_TRACE:
> 
>   If this variable is set to "1", "2" or "true" (comparison is case
>   insensitive), trace messages will be printed to stderr.
>   
>   If the variable is set to an integer value greater than 2 and lower
>   than 10 (strictly) then Git will interpret this value as an open
>   file descriptor and will try to write the trace messages into this
>   file descriptor.
> 
> The way I see it in tr2_dst_get_trace_fd() below, this applies to
> GIT_TRACE2* as well, and it even offers the possibility to specify a
> Unix Domain Socket, too.