new esy x command runs slow

[esy]

new esy x command runs slow

[jordwalke]

I updated the esy.json to be buildsInSource: "_build" and it reduced the time to one second, but still quite slow.

[andreypopp]

Yes, esy x perform build and install commands before performing the command.

Regarding build commands, I don't think we could do better than jbuilder there.

We probably can skip performing install commands in case we detect rebuild didn't happen. I'm not sure it will win much time for us though.

[andreypopp]

As jbuilder has exec subcommand this is probably the baseline:

% time esy b jbuilder exec which refmt
/Users/andreypopp/Workspace/esy-ocaml/reason/_build/install/default/bin/refmt
esy b jbuilder exec which refmt  0.10s user 0.13s system 90% cpu 0.260 total
% time esy x which refmt
/Users/andreypopp/Workspace/esy-ocaml/reason/node_modules/.cache/_esy/store/i/opam__slash__reason-3.0.2-dfe84e28/bin/refmt
esy x which refmt  0.38s user 0.71s system 88% cpu 1.238 total

[andreypopp]

Times for install:

% time esy b esy-installer > /dev/null
esy b esy-installer > /dev/null  0.14s user 0.48s system 89% cpu 0.693 total

[jordwalke]

I was seeing one second.

[jordwalke]

Should esy x skip the build commands? It would be kind of like esy cmd in that case. It runs a command in an environment resulting from whatever build has taken place.