shell> prompt very sluggish when typing first word on WSL #52765
Description
Using this expect script to test:
#!/usr/bin/expect
spawn julia +1.10
expect "julia>"
send -- ";"
expect "shell>" {
send -- "echo \"hello\"\r"
expect -re "hello\r\n$"
}
expect "shell>" {
send -- "echo \"hello\"\r"
expect -re "hello\r\n$"
}
expect "shell>" {
send -- "echo \"hello\"\r"
expect -re "hello\r\n$"
}
expect "shell>" {
send -- "echo \"hello\"\r"
expect -re "hello\r\n$"
}
expect "shell>" {
send -- "echo \"hello\"\r"
expect -re "hello\r\n$"
}
expect "shell>" {
send "\x03\x04\r"
}
expect eofOn 1.10:
$ time julia +1.10 -e ""
julia +1.10 -e "" 0.38s user 0.46s system 276% cpu 0.304 total ; start-up time only
$ time ./test_1.10.expect
expect ./test_1.10.expect 0.00s user 0.01s system 2% cpu 0.443 total ; start-up time + 5 shell commands
On latest nightly:
$ time ../../tmp/julia-c9bc2ffd52/bin/julia -e ""
../../tmp/julia-c9bc2ffd52/bin/julia -e "" 0.98s user 0.52s system 152% cpu 0.982 total ; start-up time only
$ time ./test_nightly.expect
./test_nightly.expect 0.00s user 0.01s system 0% cpu 6.719 total ; start-up time + 5 shell commands
Start-up time is 3x slower. Entering 5 shell commands takes 6.7 seconds instead of half a second on 1.10. The slow down seems to be specifically when typing the first word, for some reason.
Happens even when running with no shell customizations (zsh --no-rcs).
julia> versioninfo()
Julia Version 1.11.0-DEV.1203
Commit c9bc2ffd52e (2024-01-05 15:45 UTC)
Build Info:
Official https://julialang.org/ release
Platform Info:
OS: Linux (x86_64-linux-gnu)
CPU: 12 × 12th Gen Intel(R) Core(TM) i7-1255U
WORD_SIZE: 64
LLVM: libLLVM-15.0.7 (ORCJIT, alderlake)
Threads: 1 default, 0 interactive, 1 GC (on 12 virtual cores)