Regression in package loading time from 1.10 -> 1.11 -> nightly

[fingolfin]

We have noticed that using for several packages got quite noticeably slower from 1.10 to 1.11 to master for several of our packages.

As far as I can tell, the slowdown is before our __init__ methods get run (determined by inserting some code at the start and end of our __init__ methods that call Base.time_ns() and store the result; then comparing it with the time_ns() value just before using XYZ is executed).

Here are the summaries for Hecke. All measurements done on a MacBook Pro M1 Max with macOS 12.7.6; and a second time on a Linux machine with 2x AMD EPYC 9554 64-Core Processor.

macOS with Julia 1.10.9

julia> @time @eval using Hecke
 _    _           _
| |  | |         | |         |  Software package for
| |__| | ___  ___| | _____   |  algorithmic algebraic number theory
|  __  |/ _ \/ __| |/ / _ \  |
| |  | |  __/ (__|   <  __/  |  Manual: https://thofma.github.io/Hecke.jl
|_|  |_|\___|\___|_|\_\___|  |  Version 0.35.16-dev
  1.046861 seconds (1.02 M allocations: 71.563 MiB, 3.63% gc time, 3.74% compilation time)

macOS with Julia 1.11.4

julia> @time @eval using Hecke
 _    _           _
| |  | |         | |         |  Software package for
| |__| | ___  ___| | _____   |  algorithmic algebraic number theory
|  __  |/ _ \/ __| |/ / _ \  |
| |  | |  __/ (__|   <  __/  |  Manual: https://thofma.github.io/Hecke.jl
|_|  |_|\___|\___|_|\_\___|  |  Version 0.35.16-dev
  1.880171 seconds (3.52 M allocations: 200.677 MiB, 5.19% gc time, 27.90% compilation time: 91% of which was recompilation)

macOS with Julia nightly 1.13.0-DEV.329 (2025-03-31), Commit 6d83987

julia> @time @eval using Hecke
 _    _           _
| |  | |         | |         |  Software package for
| |__| | ___  ___| | _____   |  algorithmic algebraic number theory
|  __  |/ _ \/ __| |/ / _ \  |
| |  | |  __/ (__|   <  __/  |  Manual: https://thofma.github.io/Hecke.jl
|_|  |_|\___|\___|_|\_\___|  |  Version 0.35.16-dev
  2.507444 seconds (4.74 M allocations: 248.215 MiB, 5.57% gc time, 5.99% compilation time: 22% of which was recompilation)

Doing the same on a Linux machine with 2x AMD EPYC 9554 64-Core Processor and 1.5 TB of RAM:

With Julia 1.10.9:

julia> @time @eval using Hecke
 _    _           _
| |  | |         | |         |  Software package for
| |__| | ___  ___| | _____   |  algorithmic algebraic number theory
|  __  |/ _ \/ __| |/ / _ \  |
| |  | |  __/ (__|   <  __/  |  Manual: https://thofma.github.io/Hecke.jl
|_|  |_|\___|\___|_|\_\___|  |  Version 0.35.16-dev
  1.877488 seconds (1.03 M allocations: 73.516 MiB, 6.12% gc time, 3.49% compilation time)

With Julia 1.11.4:

julia> @time @eval using Hecke
 _    _           _
| |  | |         | |         |  Software package for
| |__| | ___  ___| | _____   |  algorithmic algebraic number theory
|  __  |/ _ \/ __| |/ / _ \  |
| |  | |  __/ (__|   <  __/  |  Manual: https://thofma.github.io/Hecke.jl
|_|  |_|\___|\___|_|\_\___|  |  Version 0.35.16-dev
  3.156934 seconds (3.93 M allocations: 226.677 MiB, 11.12% gc time, 28.32% compilation time: 88% of which was recompilation)

With Julia nightly, Version 1.13.0-DEV.340 (2025-04-01), Commit 13311f3

julia> @time @eval using Hecke
 _    _           _
| |  | |         | |         |  Software package for
| |__| | ___  ___| | _____   |  algorithmic algebraic number theory
|  __  |/ _ \/ __| |/ / _ \  |
| |  | |  __/ (__|   <  __/  |  Manual: https://thofma.github.io/Hecke.jl
|_|  |_|\___|\___|_|\_\___|  |  Version 0.35.16-dev
  4.705098 seconds (5.38 M allocations: 281.009 MiB, 11.02% gc time, 5.04% compilation time: 24% of which was recompilation)

I can also see this in other packages, e.g. GAP.jl, and even in the pure Julia AbstractAlgebra.jl (though there the numbers are all very small to start with: 0.216439 seconds -> 0.247941 seconds -> 0.421895 seconds)

[fingolfin]

CC @thofma @lgoettgens

[KristofferC]

Also kind of tracked in #57436 but more examples are good.

[IanButterworth]

The compile %'s are low, but still may be worth adding @time_imports reports. On 1.11+ if you want to catch all stdlibs, use julia -e 'Base.@time_imports using Foo'.

[KristofferC]

(The 1.11 compile time is pretty big though).

[fingolfin]

Here the results for julia -e 'Base.@time_imports using Hecke' on my MacBookPro M1 Max:

With Julia 1.10.9:

$ j10 -e 'Base.@time_imports using Hecke'
      0.3 ms  LazyArtifacts
               ┌ 0.0 ms Distributed.__init__()
     42.5 ms  Distributed 75.49% compilation time
               ┌ 5.1 ms SuiteSparse_jll.__init__()
      6.0 ms  SuiteSparse_jll
               ┌ 3.6 ms SparseArrays.CHOLMOD.__init__() 84.70% compilation time
    145.7 ms  SparseArrays 2.06% compilation time
      4.0 ms  RandomExtensions
      5.3 ms  MacroTools
      6.2 ms  Preferences
     37.1 ms  AbstractAlgebra
      0.4 ms  JLLWrappers
               ┌ 1.3 ms GMP_jll.__init__()
      1.6 ms  GMP_jll
               ┌ 0.7 ms MPFR_jll.__init__()
      1.0 ms  MPFR_jll
               ┌ 9.6 ms CompilerSupportLibraries_jll.__init__() 24.29% compilation time
     10.0 ms  CompilerSupportLibraries_jll 23.36% compilation time
               ┌ 2.4 ms OpenBLAS32_jll.__init__() 73.24% compilation time
      2.9 ms  OpenBLAS32_jll 59.49% compilation time
               ┌ 6.0 ms FLINT_jll.__init__() 89.67% compilation time
      6.5 ms  FLINT_jll 82.12% compilation time
               ┌ 152.5 ms Nemo.__init__() 2.45% compilation time
    248.8 ms  Nemo 1.50% compilation time
               ┌ 21.6 ms Hecke.__init__()
    554.8 ms  Hecke

With Julia 1.11.4:

$ j11 -e 'Base.@time_imports using Hecke'
      0.5 ms  Printf
     12.3 ms  Dates
      0.5 ms  TOML
      0.8 ms  Base64
               ┌ 0.0 ms NetworkOptions.__init__()
     58.0 ms  NetworkOptions 97.35% compilation time
               ┌ 0.8 ms MbedTLS_jll.__init__()
      2.9 ms  MbedTLS_jll
               ┌ 0.3 ms LibSSH2_jll.__init__()
      1.9 ms  LibSSH2_jll
               ┌ 1.8 ms LibGit2_jll.__init__()
      3.5 ms  LibGit2_jll
      5.2 ms  LibGit2
      6.5 ms  ArgTools
               ┌ 0.2 ms nghttp2_jll.__init__()
      2.0 ms  nghttp2_jll
               ┌ 0.6 ms LibCURL_jll.__init__()
      2.3 ms  LibCURL_jll
               ┌ 0.0 ms MozillaCACerts_jll.__init__()
      1.7 ms  MozillaCACerts_jll
               ┌ 0.0 ms LibCURL.__init__()
      1.1 ms  LibCURL
               ┌ 4.6 ms Downloads.Curl.__init__()
     18.0 ms  Downloads
      0.6 ms  Tar
               ┌ 0.1 ms p7zip_jll.__init__()
      2.5 ms  p7zip_jll
      0.2 ms  UUIDs
      0.1 ms  Logging
      6.9 ms  Markdown
               ┌ 0.0 ms Pkg.__init__()
    206.3 ms  Pkg
      0.3 ms  LazyArtifacts
      1.7 ms  InteractiveUtils
      0.7 ms  Serialization
               ┌ 0.0 ms Distributed.__init__()
     18.0 ms  Distributed 61.73% compilation time
               ┌ 4.8 ms SuiteSparse_jll.__init__()
      6.8 ms  SuiteSparse_jll
               ┌ 4.8 ms SparseArrays.CHOLMOD.__init__() 87.99% compilation time
    103.4 ms  SparseArrays 4.07% compilation time
      4.1 ms  RandomExtensions
      5.4 ms  MacroTools
      5.7 ms  Preferences
     38.4 ms  AbstractAlgebra
      0.4 ms  JLLWrappers
               ┌ 1.6 ms GMP_jll.__init__()
      3.2 ms  GMP_jll
               ┌ 1.0 ms MPFR_jll.__init__()
      2.7 ms  MPFR_jll
               ┌ 8.5 ms CompilerSupportLibraries_jll.__init__()
     10.8 ms  CompilerSupportLibraries_jll
               ┌ 9.1 ms OpenBLAS32_jll.__init__() 93.18% compilation time
      9.7 ms  OpenBLAS32_jll 87.44% compilation time
               ┌ 8.4 ms FLINT_jll.__init__() 91.68% compilation time
      9.0 ms  FLINT_jll 85.32% compilation time
               ┌ 164.5 ms Nemo.__init__() 14.96% compilation time
    283.8 ms  Nemo 8.67% compilation time
               ┌ 32.6 ms Hecke.__init__()
    868.5 ms  Hecke

With Julia nightly 1.13.0-DEV.329 (2025-03-31), Commit 6d83987:

$ jnightly -e 'Base.@time_imports using Hecke'
A new `nightly` version is available. Install with `juliaup update`.
      5.3 ms  Printf
     20.7 ms  Dates
      4.8 ms  TOML
               ┌ 0.0 ms NetworkOptions.__init__()
     96.3 ms  NetworkOptions 99.19% compilation time
               ┌ 14.5 ms OpenSSL_jll.__init__()
     18.8 ms  OpenSSL_jll
               ┌ 5.1 ms LibSSH2_jll.__init__()
      9.8 ms  LibSSH2_jll
               ┌ 6.8 ms LibGit2_jll.__init__()
     11.7 ms  LibGit2_jll
     13.1 ms  LibGit2
     14.5 ms  ArgTools
               ┌ 4.3 ms nghttp2_jll.__init__()
      9.0 ms  nghttp2_jll
               ┌ 0.6 ms Zlib_jll.__init__()
      4.9 ms  Zlib_jll
               ┌ 5.4 ms LibCURL_jll.__init__()
      9.2 ms  LibCURL_jll
               ┌ 0.0 ms MozillaCACerts_jll.__init__()
      3.9 ms  MozillaCACerts_jll
               ┌ 0.0 ms LibCURL.__init__()
      5.1 ms  LibCURL
               ┌ 4.2 ms Downloads.Curl.__init__()
     19.6 ms  Downloads
      5.6 ms  Tar
               ┌ 0.1 ms p7zip_jll.__init__()
      0.5 ms  p7zip_jll
      4.5 ms  UUIDs
      3.7 ms  Logging
      5.3 ms  Base64
    111.3 ms  StyledStrings
               ┌ 0.1 ms JuliaSyntaxHighlighting.__init__()
     10.0 ms  JuliaSyntaxHighlighting
               ┌ 0.1 ms Markdown.__init__()
     22.2 ms  Markdown
               ┌ 0.0 ms Pkg.__init__()
    280.6 ms  Pkg
      4.3 ms  LazyArtifacts
      6.6 ms  InteractiveUtils
      4.8 ms  Serialization
               ┌ 0.1 ms Distributed.__init__()
     51.6 ms  Distributed 75.22% compilation time
               ┌ 192.2 ms SuiteSparse_jll.__init__()
    196.6 ms  SuiteSparse_jll
               ┌ 5.1 ms SparseArrays.CHOLMOD.__init__() 74.09% compilation time
    143.9 ms  SparseArrays 2.63% compilation time
      6.7 ms  RandomExtensions
     12.3 ms  MacroTools
      1.5 ms  Preferences
     76.5 ms  AbstractAlgebra
      0.6 ms  JLLWrappers
               ┌ 5.3 ms GMP_jll.__init__()
      9.8 ms  GMP_jll
               ┌ 1.1 ms MPFR_jll.__init__()
      5.1 ms  MPFR_jll
               ┌ 70.0 ms OpenBLAS32_jll.__init__() 98.79% compilation time
     70.6 ms  OpenBLAS32_jll 98.03% compilation time
               ┌ 8.3 ms FLINT_jll.__init__() 93.04% compilation time
      8.9 ms  FLINT_jll 86.27% compilation time
               ┌ 199.5 ms Nemo.__init__() 27.38% compilation time (66% recompilation)
    351.8 ms  Nemo 15.53% compilation time (66% recompilation)
               ┌ 28.4 ms Hecke.__init__() 14.40% compilation time
   2100.6 ms  Hecke 0.19% compilation time

[fingolfin]

So from 1.10 to 1.11 there is a noticeable slowdown caused by Pkg (~200ms), but everything in general seems to have slowed down.

From 1.11 to master, loading Pkg got even slower, but now also bunch of JLLs got slower. E.g.:

1.10:

               ┌ 5.1 ms SuiteSparse_jll.__init__()
      6.0 ms  SuiteSparse_jll

               ┌ 2.4 ms OpenBLAS32_jll.__init__() 73.24% compilation time
      2.9 ms  OpenBLAS32_jll 59.49% compilation time

1.11:

               ┌ 4.8 ms SuiteSparse_jll.__init__()
      6.8 ms  SuiteSparse_jll

               ┌ 9.1 ms OpenBLAS32_jll.__init__() 93.18% compilation time
      9.7 ms  OpenBLAS32_jll 87.44% compilation time

master:

               ┌ 192.2 ms SuiteSparse_jll.__init__()
    196.6 ms  SuiteSparse_jll

               ┌ 70.0 ms OpenBLAS32_jll.__init__() 98.79% compilation time
     70.6 ms  OpenBLAS32_jll 98.03% compilation time

So those JLL slowdowns are massive

[fingolfin]

I was very happy to see issue #57436 resolved via various patches, and was hoping this issue here was also resolved with Julia 1.12.0-rc2 Alas, it is not, and indeed 1.12 is still worse than 1.11, which is worse than 1.10...

Timings on a Linux machine with AMD EPYC 9554 64-Core CPU:

tutulla:~$ hyperfine 'julia +1.10 --startup-file=no -e "using Hecke"' 'julia +1.11 --startup-file=no -e "using Hecke"' 'julia +1.12 --startup-file=no -e "using Hecke"'
Benchmark 1: julia +1.10 --startup-file=no -e "using Hecke"
  Time (mean ± σ):      1.675 s ±  0.025 s    [User: 2.048 s, System: 5.043 s]
  Range (min … max):    1.644 s …  1.718 s    10 runs

Benchmark 2: julia +1.11 --startup-file=no -e "using Hecke"
  Time (mean ± σ):      2.111 s ±  0.038 s    [User: 7.204 s, System: 0.368 s]
  Range (min … max):    2.073 s …  2.186 s    10 runs

Benchmark 3: julia +1.12 --startup-file=no -e "using Hecke"
  Time (mean ± σ):      2.288 s ±  0.150 s    [User: 7.361 s, System: 0.388 s]
  Range (min … max):    2.148 s …  2.642 s    10 runs

Summary
  julia +1.10 --startup-file=no -e "using Hecke" ran
    1.26 ± 0.03 times faster than julia +1.11 --startup-file=no -e "using Hecke"
    1.37 ± 0.09 times faster than julia +1.12 --startup-file=no -e "using Hecke"

Timings on an Mac Mini m1:

munk:~$ hyperfine 'julia +1.10 --startup-file=no -e "using Hecke"' 'julia +1.11 --startup-file=no -e "using Hecke"' 'julia +1.12 --startup-file=no -e "using Hecke"'
Benchmark 1: julia +1.10 --startup-file=no -e "using Hecke"
  Time (mean ± σ):     955.9 ms ±   0.9 ms    [User: 1633.0 ms, System: 99.1 ms]
  Range (min … max):   954.8 ms … 957.5 ms    10 runs

Benchmark 2: julia +1.11 --startup-file=no -e "using Hecke"
  Time (mean ± σ):      1.281 s ±  0.002 s    [User: 1.910 s, System: 0.144 s]
  Range (min … max):    1.279 s …  1.287 s    10 runs

Benchmark 3: julia +1.12 --startup-file=no -e "using Hecke"
  Time (mean ± σ):      1.577 s ±  0.003 s    [User: 2.210 s, System: 0.142 s]
  Range (min … max):    1.573 s …  1.584 s    10 runs

Summary
  julia +1.10 --startup-file=no -e "using Hecke" ran
    1.34 ± 0.00 times faster than julia +1.11 --startup-file=no -e "using Hecke"
    1.65 ± 0.00 times faster than julia +1.12 --startup-file=no -e "using Hecke"

[fingolfin]

Some more data, measured on the Linux machine:

~/Projekte/OSCAR/flint (git:main)$ ssh tutulla
Welcome on tutulla, the compute server of AG Horn.

Last login: Tue Sep  9 17:30:47 2025 from skylla.mathematik.uni-kl.de
Agent pid 45399
tutulla:~$ julia +1.10  -e 'Base.@time_imports using Hecke'
               ┌ 0.1 ms Distributed.__init__()
     62.1 ms  Distributed 71.68% compilation time
               ┌ 0.7 ms SuiteSparse_jll.__init__()
      1.2 ms  SuiteSparse_jll
               ┌ 6.3 ms SparseArrays.CHOLMOD.__init__() 93.87% compilation time
    114.4 ms  SparseArrays 5.17% compilation time
      5.1 ms  RandomExtensions
      7.3 ms  MacroTools
      7.8 ms  Preferences
     52.2 ms  AbstractAlgebra
      0.5 ms  JLLWrappers
               ┌ 0.1 ms GMP_jll.__init__()
      0.3 ms  GMP_jll
               ┌ 0.0 ms MPFR_jll.__init__()
      0.1 ms  MPFR_jll
               ┌ 4.7 ms CompilerSupportLibraries_jll.__init__() 92.92% compilation time
      5.0 ms  CompilerSupportLibraries_jll 87.81% compilation time
               ┌ 4.8 ms OpenBLAS32_jll.__init__() 62.03% compilation time
      5.3 ms  OpenBLAS32_jll 56.46% compilation time
               ┌ 12.3 ms FLINT_jll.__init__() 91.98% compilation time
     12.7 ms  FLINT_jll 88.78% compilation time
               ┌ 271.5 ms Nemo.__init__() 2.77% compilation time
    387.4 ms  Nemo 1.94% compilation time
               ┌ 180.8 ms Hecke.__init__()
    736.8 ms  Hecke

$ julia +1.11  -e 'Base.@time_imports using Hecke'
      1.1 ms  Serialization
               ┌ 0.0 ms Distributed.__init__()
    121.2 ms  Distributed 91.80% compilation time
      0.6 ms  Printf
               ┌ 0.6 ms SuiteSparse_jll.__init__()
      3.1 ms  SuiteSparse_jll
               ┌ 8.6 ms SparseArrays.CHOLMOD.__init__() 95.28% compilation time
    103.1 ms  SparseArrays 7.98% compilation time
     18.8 ms  Dates
      0.5 ms  TOML
      0.8 ms  Base64
               ┌ 0.0 ms NetworkOptions.__init__()
      1.8 ms  NetworkOptions
               ┌ 0.3 ms MbedTLS_jll.__init__()
      2.1 ms  MbedTLS_jll
               ┌ 0.1 ms LibSSH2_jll.__init__()
      1.7 ms  LibSSH2_jll
               ┌ 0.1 ms LibGit2_jll.__init__()
      1.6 ms  LibGit2_jll
      6.4 ms  LibGit2
     49.6 ms  ArgTools
               ┌ 0.1 ms nghttp2_jll.__init__()
      2.3 ms  nghttp2_jll
               ┌ 0.2 ms LibCURL_jll.__init__()
      1.8 ms  LibCURL_jll
               ┌ 0.0 ms MozillaCACerts_jll.__init__()
      1.9 ms  MozillaCACerts_jll
               ┌ 0.0 ms LibCURL.__init__()
      1.2 ms  LibCURL
               ┌ 0.2 ms Downloads.Curl.__init__()
     17.1 ms  Downloads
      0.9 ms  Tar
               ┌ 0.1 ms p7zip_jll.__init__()
      2.9 ms  p7zip_jll
      0.1 ms  UUIDs
      0.1 ms  Logging
      9.6 ms  Markdown
               ┌ 0.0 ms Pkg.__init__()
    237.5 ms  Pkg
      5.7 ms  RandomExtensions
      8.5 ms  MacroTools
      7.0 ms  Preferences
     54.5 ms  AbstractAlgebra
      0.5 ms  JLLWrappers
               ┌ 0.1 ms GMP_jll.__init__()
      2.4 ms  GMP_jll
               ┌ 0.0 ms MPFR_jll.__init__()
      2.0 ms  MPFR_jll
               ┌ 0.3 ms CompilerSupportLibraries_jll.__init__()
      3.2 ms  CompilerSupportLibraries_jll
               ┌ 6.2 ms OpenBLAS32_jll.__init__() 68.34% compilation time
      6.6 ms  OpenBLAS32_jll 64.20% compilation time
               ┌ 25.8 ms FLINT_jll.__init__() 95.95% compilation time
     26.3 ms  FLINT_jll 93.97% compilation time
               ┌ 261.8 ms Nemo.__init__() 19.31% compilation time
    372.5 ms  Nemo 13.57% compilation time
               ┌ 168.5 ms Hecke.__init__()
    903.7 ms  Hecke

$ julia +1.12  -e 'Base.@time_imports using Hecke'
      1.2 ms  Serialization
               ┌ 0.0 ms Distributed.__init__()
    155.7 ms  Distributed 93.58% compilation time
      0.7 ms  Printf
               ┌ 0.6 ms SuiteSparse_jll.__init__()
      0.9 ms  SuiteSparse_jll
               ┌ 0.2 ms SparseArrays.CHOLMOD.__init__()
    220.4 ms  SparseArrays
     22.2 ms  Dates
      0.6 ms  TOML
      0.3 ms  NetworkOptions
               ┌ 0.6 ms OpenSSL_jll.__init__()
      0.8 ms  OpenSSL_jll
               ┌ 0.1 ms LibSSH2_jll.__init__()
      0.3 ms  LibSSH2_jll
               ┌ 0.1 ms LibGit2_jll.__init__()
      0.2 ms  LibGit2_jll
      7.2 ms  LibGit2
      6.1 ms  ArgTools
               ┌ 0.1 ms nghttp2_jll.__init__()
      0.3 ms  nghttp2_jll
               ┌ 0.0 ms Zlib_jll.__init__()
      0.2 ms  Zlib_jll
               ┌ 0.1 ms LibCURL_jll.__init__()
      0.3 ms  LibCURL_jll
               ┌ 0.0 ms MozillaCACerts_jll.__init__()
      0.1 ms  MozillaCACerts_jll
               ┌ 0.0 ms LibCURL.__init__()
      1.3 ms  LibCURL
               ┌ 0.6 ms Downloads.Curl.__init__()
      7.8 ms  Downloads
      1.2 ms  Tar
               ┌ 0.0 ms p7zip_jll.__init__()
      0.3 ms  p7zip_jll
      0.1 ms  UUIDs
      0.1 ms  Logging
      0.5 ms  Base64
     25.1 ms  StyledStrings
               ┌ 0.1 ms JuliaSyntaxHighlighting.__init__()
     19.3 ms  JuliaSyntaxHighlighting
               ┌ 0.0 ms Markdown.__init__()
      9.9 ms  Markdown
               ┌ 0.0 ms Pkg.__init__()
    152.8 ms  Pkg
      4.6 ms  RandomExtensions
      3.7 ms  MacroTools
      0.5 ms  Preferences
     67.7 ms  AbstractAlgebra
      0.6 ms  JLLWrappers
               ┌ 0.1 ms GMP_jll.__init__()
      0.3 ms  GMP_jll
               ┌ 0.0 ms MPFR_jll.__init__()
      0.1 ms  MPFR_jll
               ┌ 0.2 ms CompilerSupportLibraries_jll.__init__()
      0.4 ms  CompilerSupportLibraries_jll
               ┌ 1.9 ms OpenBLAS32_jll.__init__()
      2.1 ms  OpenBLAS32_jll
               ┌ 19.2 ms FLINT_jll.__init__() 94.81% compilation time
     19.5 ms  FLINT_jll 93.12% compilation time
               ┌ 93.3 ms Nemo.__init__() 23.07% compilation time
    279.9 ms  Nemo 7.69% compilation time
               ┌ 18.4 ms Hecke.__init__()
   1010.8 ms  Hecke

So a substantial part comes from Pkg being a dependency (it's not just Pkg.jl itself, but also its various dependencies). We can try to get rid of it, but I think this affects a lot of other packages, too.