Re: [PATCH 1/2] trace2: rename environment variables to GIT_TRACE2*

[Jeff Hostetler <git@jeffhostetler.com>]

On 5/28/2019 7:02 PM, Ævar Arnfjörð Bjarmason wrote:
> 
> On Sun, May 19 2019, SZEDER Gábor wrote:
> 
>> For an environment variable that is supposed to be set by users, the
>> GIT_TR2* env vars are just too unclear, inconsistent, and ugly.
>>
>> Most of the established GIT_* environment variables don't use
>> abbreviations, and in case of the few that do (GIT_DIR,
>> GIT_COMMON_DIR, GIT_DIFF_OPTS) it's quite obvious what the
>> abbreviations (DIR and OPTS) stand for.  But what does TR stand for?
>> Track, traditional, trailer, transaction, transfer, transformation,
>> transition, translation, transplant, transport, traversal, tree,
>> trigger, truncate, trust, or ...?!
>>
>> The trace2 facility, as the '2' suffix in its name suggests, is
>> supposed to eventually supercede Git's original trace facility.  It's
>> reasonable to expect that the corresponding environment variables
>> follow suit, and after the original GIT_TRACE variables they are
>> called GIT_TRACE2; there is no such thing is 'GIT_TR'.
>>
>> All trace2-specific config variables are, very sensibly, in the
>> 'trace2' section, not in 'tr2'.
>>
>> OTOH, we don't gain anything at all by omitting the last three
>> characters of "trace" from the names of these environment variables.
>>
>> So let's rename all GIT_TR2* environment variables to GIT_TRACE2*,
>> before they make their way into a stable release.
> 
> Good to see this land in 2.22.0. I wonder if we shouldn't take this
> further and rename trace2.* config to trace.*, and just re-use
> GIT_TRACE=1 instead of having GIT_TRACE2 as well, and have a
> GIT_TRACE_VERSION to switch between them.
> 
> Then we could just switch in a future version. We've never promised what
> the trace format was going to look like, and the existing one isn't
> configurable (and we won't be making the v1 one...), so starting from
> the outset with "2" in config is unfortunate.
> 
> We'd still have special snowflakes like e.g. GIT_TRACE_PACKET.
> 
> OTOH we can just do this after the release if it's deemed a good idea,
> and just support trace2.* as aliases for trace.* for some amount of
> time, same for the env vars.
> 

I'm open to considering such a change while we're at it.

Jeff