Got the new alpha from juliaup, and the REPL seemed significantly slower to boot than in the release.
Did a very simple test where I pressed Ctrl-D as soon as I saw the julia prompt, so might be a little variability from that but hardly 2 seconds.
❯ time julia +alpha
_
_ _ _(_)_ | Documentation: https://docs.julialang.org
(_) | (_) (_) |
_ _ _| |_ __ _ | Type "?" for help, "]?" for Pkg help.
| | | | | | |/ _` | |
| | |_| | | | (_| | | Version 1.10.0-alpha1 (2023-07-06)
_/ |\__'_|_|_|\__'_| | Official https://julialang.org/ release
|__/ |
julia>
________________________________________________________
Executed in 5.30 secs fish external
usr time 5.00 secs 0.00 millis 5.00 secs
sys time 0.76 secs 1.00 millis 0.76 secs
❯ time julia +release
_
_ _ _(_)_ | Documentation: https://docs.julialang.org
(_) | (_) (_) |
_ _ _| |_ __ _ | Type "?" for help, "]?" for Pkg help.
| | | | | | |/ _` | |
| | |_| | | | (_| | | Version 1.9.2 (2023-07-05)
_/ |\__'_|_|_|\__'_| | Official https://julialang.org/ release
|__/ |
julia>
________________________________________________________
Executed in 3.27 secs fish external
usr time 2.92 secs 427.00 micros 2.92 secs
sys time 0.57 secs 106.00 micros 0.57 secs
Can’t confirm on my machine (Apple M1 Mac):
➜ ~
$ time julia +release -e 'nothing'
julia +release -e 'nothing' 0.18s user 0.06s system 131% cpu 0.179 total
➜ ~
$ time julia +alpha -e 'nothing'
julia +alpha -e 'nothing' 0.18s user 0.06s system 128% cpu 0.185 total
➜ ~
$ time julia +release
_
_ _ _(_)_ | Documentation: https://docs.julialang.org
(_) | (_) (_) |
_ _ _| |_ __ _ | Type "?" for help, "]?" for Pkg help.
| | | | | | |/ _` | |
| | |_| | | | (_| | | Version 1.9.2 (2023-07-05)
_/ |\__'_|_|_|\__'_| | Official https://julialang.org/ release
|__/ |
julia>
julia +release 1.04s user 0.12s system 176% cpu 0.658 total
➜ ~
$ time julia +alpha
_
_ _ _(_)_ | Documentation: https://docs.julialang.org
(_) | (_) (_) |
_ _ _| |_ __ _ | Type "?" for help, "]?" for Pkg help.
| | | | | | |/ _` | |
| | |_| | | | (_| | | Version 1.10.0-alpha1 (2023-07-06)
_/ |\__'_|_|_|\__'_| | Official https://julialang.org/ release
|__/ |
julia>
julia +alpha 1.04s user 0.08s system 156% cpu 0.714 total
Okay, that is nice. Hope it is just something on my setup then.
I also tried the -e "nothing" at first, though for me that was faster for alpha. So it seemed like it was something specifically tied to the REPL that added like 50% more time 
It’s very quick for me:
> time julia +alpha --startup-file=no
real 0m0,375s
user 0m0,435s
sys 0m0,673s
Do you have something expensive in your startup file?
3 Likes
Thanks, feel a bit stupid now 
Without startup it is pretty instant, and after commenting out some things in it I found that AbbreviatedStackTraces.jl seems to be the one causing most of the delay in both versions and specifically the noticable difference in delay.
Will probably leave it out based on this, though I do like the package so it feels a bit sad.
2 Likes
Julia 1.10 does have limited stack traces: (#49795, #49959)
It’s not to the extent that AbbreviatedStackTraces has it, but it’s something.
7 Likes
Also note that you’re testing an alpha version of Julia 1.10 that literally just came out. Most packages haven’t had time to adapt to changes yet. Maybe there’s something that AbbreviatedStackTraces.jl can do to improve for 1.10. A little patience could be enough 
4 Likes
The main thing AbbreviatedStatckTraces.jl should probably do is check if the version is 1.10 or higher and if so disable itself
1 Like
That sounds strange since a large point of AbbreviatedStatckTraces is to hide stack frames that are deemed uninteresting and that part has not been changed in Julia itself.
6 Likes
Sadly, AbbreviatedStackTraces has to reach deep into Julia to overwrite key REPL functions, resulting in a lot of recompilation.
I’ll need to harmonize it with 1.10 so that it’s not bypassing whatever changes were made to stack traces there. But probably won’t change the performance.
And Kristoffer is correct, it goes further than what’s in 1.10 so I’m not done with this package
10 Likes