Share Julia depot cache

[j178]

Use a prek-managed shared Julia depot so hook environments reuse packages and precompile caches without writing to the user's default depot.

Refs pre-commit/pre-commit#3711.

[Copilot]

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[codecov]

Codecov Report

❌ Patch coverage is 85.71429% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 93.33%. Comparing base (0265ddd) to head (7392da3).

Files with missing lines	Patch %	Lines
crates/prek/src/languages/mod.rs	0.00%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #2357   +/-   ##
=======================================
  Coverage   93.33%   93.33%           
=======================================
  Files         128      128           
  Lines       27233    27240    +7     
=======================================
+ Hits        25417    25424    +7     
  Misses       1816     1816           

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[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Invalidate old Julia envs before switching depots

When users upgrade with an already-installed Julia hook environment, the install cache still considers it reusable because the persisted metadata/schema did not change and check_health only runs julia --version. Those old environments had their package sources in the user's default depot, but this runtime override points Julia at a new prek depot and excludes the user depot, so hooks that use additional_dependencies or a Project.toml dependency can fail to load packages until the user manually reinstalls. Please make old Julia envs miss the cache or instantiate them into the shared depot before running them with this JULIA_DEPOT_PATH.

Useful? React with 👍 / 👎.

[prek-ci-bot]

📦 Cargo Bloat Comparison

Binary size change: -0.34% (29.0 MiB → 28.9 MiB)

Expand for cargo-bloat output

Head Branch Results

 File  .text     Size             Crate Name
 1.1%   2.4% 332.0KiB        aws_lc_sys aws_lc_0_42_0_aes_gcm_encrypt_avx512
 1.1%   2.4% 332.0KiB        aws_lc_sys aws_lc_0_42_0_aes_gcm_decrypt_avx512
 0.3%   0.6%  79.3KiB              prek <prek::cli::Command as clap_builder::derive::Subcommand>::augment_subcommands
 0.2%   0.4%  50.5KiB              prek <<prek::config::Config as serde_core::de::Deserialize>::deserialize::__Visitor as serde_core::de::Visitor>::visit_map::<<serde_saphyr::de::deserializer::YamlDeserializer as serde_core::de::Deserializer>::deserialize_map::MA>
 0.2%   0.4%  49.4KiB annotate_snippets annotate_snippets::renderer::render::render
 0.2%   0.3%  48.3KiB              prek prek::run::{closure#0}
 0.1%   0.3%  42.6KiB              prek prek::cli::run::run::run::{closure#0}
 0.1%   0.2%  32.1KiB              prek <prek::cli::RunOptions as clap_builder::derive::Args>::augment_args
 0.1%   0.2%  29.5KiB     granit_parser <granit_parser::scanner::Scanner<granit_parser::input::str::StrInput>>::fetch_more_tokens
 0.1%   0.2%  28.6KiB    cargo_metadata <&mut serde_json::de::Deserializer<serde_json::read::StrRead> as serde_core::de::Deserializer>::deserialize_struct::<<cargo_metadata::Package as serde_core::de::Deserialize>::deserialize::__Visitor>
 0.1%   0.2%  28.0KiB        aws_lc_sys aws_lc_0_42_0_edwards25519_scalarmuldouble_alt
 0.1%   0.2%  27.5KiB        aws_lc_sys aws_lc_0_42_0_edwards25519_scalarmuldouble
 0.1%   0.2%  26.8KiB              prek <<prek::config::RemoteHook as serde_core::de::Deserialize>::deserialize::__Visitor as serde_core::de::Visitor>::visit_map::<<serde_saphyr::de::deserializer::YamlDeserializer as serde_core::de::Deserializer>::deserialize_map::MA>
 0.1%   0.2%  25.8KiB              prek prek::cli::try_repo::try_repo::{closure#0}
 0.1%   0.2%  24.9KiB               xml <xml::reader::parser::PullParser>::dispatch_token
 0.1%   0.2%  24.3KiB              prek <prek::languages::node::installer::NodeInstaller>::install::{closure#0}
 0.1%   0.2%  23.8KiB              prek <<prek::config::LocalHook as serde_core::de::Deserialize>::deserialize::__Visitor as serde_core::de::Visitor>::visit_map::<<serde_saphyr::de::deserializer::YamlDeserializer as serde_core::de::Deserializer>::deserialize_map::MA>
 0.1%   0.2%  23.2KiB              prek <<prek::config::UpdateOptions as serde_core::de::Deserialize>::deserialize::__Visitor as serde_core::de::Visitor>::visit_map::<<serde_saphyr::de::deserializer::YamlDeserializer as serde_core::de::Deserializer>::deserialize_map::MA>
 0.1%   0.2%  22.3KiB         [Unknown] Lp384_montjscalarmul_alt_p384_montjadd
 0.1%   0.2%  22.3KiB              prek <prek::languages::rust::rust::Rust as prek::languages::LanguageBackend>::install::{closure#0}
42.0%  88.1%  12.1MiB                   And 25575 smaller methods. Use -n N to show more.
47.7% 100.0%  13.8MiB                   .text section size, the file size is 28.9MiB

Base Branch Results

 File  .text     Size             Crate Name
 1.1%   2.3% 332.0KiB        aws_lc_sys aws_lc_0_42_0_aes_gcm_encrypt_avx512
 1.1%   2.3% 332.0KiB        aws_lc_sys aws_lc_0_42_0_aes_gcm_decrypt_avx512
 0.3%   0.6%  79.7KiB              prek <prek::cli::Command as clap_builder::derive::Subcommand>::augment_subcommands
 0.2%   0.4%  52.3KiB              prek <<prek::config::Config as serde_core::de::Deserialize>::deserialize::__Visitor as serde_core::de::Visitor>::visit_map::<<serde_saphyr::de::deserializer::YamlDeserializer as serde_core::de::Deserializer>::deserialize_map::MA>
 0.2%   0.3%  49.4KiB annotate_snippets annotate_snippets::renderer::render::render
 0.1%   0.3%  43.3KiB              prek prek::cli::run::run::run::{closure#0}
 0.1%   0.3%  40.1KiB              prek prek::run::{closure#0}
 0.1%   0.2%  31.9KiB              prek <prek::cli::RunOptions as clap_builder::derive::Args>::augment_args
 0.1%   0.2%  30.1KiB              prek prek::cli::update::update::{closure#0}
 0.1%   0.2%  29.5KiB     granit_parser <granit_parser::scanner::Scanner<granit_parser::input::str::StrInput>>::fetch_more_tokens
 0.1%   0.2%  28.6KiB    cargo_metadata <&mut serde_json::de::Deserializer<serde_json::read::StrRead> as serde_core::de::Deserializer>::deserialize_struct::<<cargo_metadata::Package as serde_core::de::Deserialize>::deserialize::__Visitor>
 0.1%   0.2%  28.2KiB              prek <<prek::config::RemoteHook as serde_core::de::Deserialize>::deserialize::__Visitor as serde_core::de::Visitor>::visit_map::<<serde_saphyr::de::deserializer::YamlDeserializer as serde_core::de::Deserializer>::deserialize_map::MA>
 0.1%   0.2%  28.0KiB        aws_lc_sys aws_lc_0_42_0_edwards25519_scalarmuldouble_alt
 0.1%   0.2%  27.5KiB        aws_lc_sys aws_lc_0_42_0_edwards25519_scalarmuldouble
 0.1%   0.2%  26.9KiB              prek prek::cli::try_repo::try_repo::{closure#0}
 0.1%   0.2%  25.6KiB              prek <<prek::config::LocalHook as serde_core::de::Deserialize>::deserialize::__Visitor as serde_core::de::Visitor>::visit_map::<<serde_saphyr::de::deserializer::YamlDeserializer as serde_core::de::Deserializer>::deserialize_map::MA>
 0.1%   0.2%  25.2KiB              prek <<prek::config::UpdateOptions as serde_core::de::Deserialize>::deserialize::__Visitor as serde_core::de::Visitor>::visit_map::<<serde_saphyr::de::deserializer::YamlDeserializer as serde_core::de::Deserializer>::deserialize_map::MA>
 0.1%   0.2%  24.9KiB               xml <xml::reader::parser::PullParser>::dispatch_token
 0.1%   0.2%  23.8KiB              prek <prek::languages::node::installer::NodeInstaller>::install::{closure#0}
 0.1%   0.2%  22.3KiB         [Unknown] Lp384_montjscalarmul_alt_p384_montjadd
42.0%  88.1%  12.2MiB                   And 25599 smaller methods. Use -n N to show more.
47.7% 100.0%  13.8MiB                   .text section size, the file size is 29.0MiB

[prek-ci-bot]

⚡️ Hyperfine Benchmarks

Summary: 0 regressions, 4 improvements above the 10% threshold.

Environment

• OS: Linux 6.17.0-1018-azure
• CPU: 4 cores
• prek version: prek 0.4.9+33 (b1c8310 2026-07-16)
• Rust version: rustc 1.97.0 (2d8144b78 2026-07-07)
• Hyperfine version: hyperfine 1.20.0

CLI Commands

Benchmarking basic commands in the main repo:

prek --version

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base --version	1.9 ± 0.1	1.8	2.3	1.00
prek-head --version	1.9 ± 0.0	1.8	2.2	1.00 ± 0.05

prek list

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base list	10.8 ± 20.4	7.6	195.9	1.18 ± 2.47
prek-head list	9.1 ± 8.1	7.7	88.2	1.00

✅ Performance improvement for prek list: 15.2900% faster

prek validate-config .pre-commit-config.yaml

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base validate-config .pre-commit-config.yaml	2.8 ± 0.1	2.7	3.0	1.00
prek-head validate-config .pre-commit-config.yaml	2.9 ± 0.5	2.8	6.1	1.03 ± 0.17

prek sample-config

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base sample-config	2.2 ± 0.2	2.1	3.7	1.04 ± 0.10
prek-head sample-config	2.2 ± 0.1	2.1	2.3	1.00

Cold vs Warm Runs

Comparing first run (cold) vs subsequent runs (warm cache):

prek run --all-files (cold - no cache)

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run --all-files	61.3 ± 2.9	58.5	68.7	1.01 ± 0.07
prek-head run --all-files	60.9 ± 2.7	57.0	65.6	1.00

prek run --all-files (warm - with cache)

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run --all-files	60.5 ± 1.7	57.2	62.9	1.00
prek-head run --all-files	62.7 ± 2.7	58.7	67.3	1.04 ± 0.05

Full Hook Suite

Running the builtin hook suite on the benchmark workspace:

prek run --all-files (full builtin hook suite)

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run --all-files	61.4 ± 2.5	56.4	65.9	1.02 ± 0.06
prek-head run --all-files	60.4 ± 2.6	56.4	66.0	1.00

Individual Hook Performance

Benchmarking each hook individually on the test repo:

prek run trailing-whitespace --all-files

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run trailing-whitespace --all-files	17.1 ± 2.8	16.0	31.7	1.04 ± 0.17
prek-head run trailing-whitespace --all-files	16.4 ± 0.3	15.8	17.0	1.00

prek run end-of-file-fixer --all-files

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run end-of-file-fixer --all-files	21.9 ± 1.6	19.7	25.1	1.00
prek-head run end-of-file-fixer --all-files	22.9 ± 6.2	19.3	54.5	1.05 ± 0.29

prek run check-json --all-files

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run check-json --all-files	8.2 ± 5.9	6.4	38.5	1.11 ± 0.97
prek-head run check-json --all-files	7.4 ± 3.7	6.4	27.2	1.00

prek run check-yaml --all-files

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run check-yaml --all-files	7.1 ± 1.2	6.5	12.6	1.07 ± 0.19
prek-head run check-yaml --all-files	6.6 ± 0.1	6.4	6.8	1.00

prek run check-toml --all-files

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run check-toml --all-files	6.7 ± 0.2	6.4	7.1	1.01 ± 0.05
prek-head run check-toml --all-files	6.7 ± 0.2	6.3	7.1	1.00

prek run check-xml --all-files

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run check-xml --all-files	6.9 ± 1.3	6.3	13.9	1.00
prek-head run check-xml --all-files	7.3 ± 3.6	6.2	26.4	1.05 ± 0.56

prek run detect-private-key --all-files

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run detect-private-key --all-files	11.6 ± 0.8	10.1	13.5	1.05 ± 0.20
prek-head run detect-private-key --all-files	11.1 ± 2.0	9.6	20.7	1.00

prek run fix-byte-order-marker --all-files

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run fix-byte-order-marker --all-files	15.0 ± 0.6	14.0	16.3	1.00 ± 0.05
prek-head run fix-byte-order-marker --all-files	14.9 ± 0.5	13.9	16.0	1.00

Installation Performance

Benchmarking hook installation (fast path hooks skip Python setup):

prek install-hooks (cold - no cache)

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base install-hooks	4.0 ± 0.0	4.0	4.1	1.00
prek-head install-hooks	4.1 ± 0.1	4.0	4.2	1.03 ± 0.02

prek install-hooks (warm - with cache)

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base install-hooks	4.0 ± 0.1	3.9	4.1	1.01 ± 0.03
prek-head install-hooks	4.0 ± 0.0	4.0	4.0	1.00

File Filtering/Scoping Performance

Testing different file selection modes:

prek run (staged files only)

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run	32.5 ± 0.9	31.0	34.2	1.00
prek-head run	32.9 ± 2.7	31.3	43.2	1.01 ± 0.09

prek run --files '*.json' (specific file type)

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run --files '*.json'	7.6 ± 0.2	7.2	8.1	1.04 ± 0.04
prek-head run --files '*.json'	7.4 ± 0.2	7.0	7.8	1.00

Workspace Discovery & Initialization

Benchmarking hook discovery and initialization overhead:

prek run --dry-run --all-files (measures init overhead)

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run --dry-run --all-files	7.0 ± 2.8	5.9	15.8	1.10 ± 0.49
prek-head run --dry-run --all-files	6.4 ± 1.2	5.9	11.4	1.00

Meta Hooks Performance

Benchmarking meta hooks separately:

prek run check-hooks-apply --all-files

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run check-hooks-apply --all-files	10.7 ± 0.2	10.3	11.1	1.11 ± 0.06
prek-head run check-hooks-apply --all-files	9.6 ± 0.5	9.2	11.3	1.00

✅ Performance improvement for prek run check-hooks-apply --all-files: 10.0600% faster

prek run check-useless-excludes --all-files

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run check-useless-excludes --all-files	17.7 ± 31.6	9.3	131.8	1.12 ± 2.51
prek-head run check-useless-excludes --all-files	15.8 ± 21.4	9.3	92.6	1.00

✅ Performance improvement for prek run check-useless-excludes --all-files: 10.8800% faster

prek run identity --all-files

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run identity --all-files	11.1 ± 5.6	8.7	28.7	1.24 ± 0.63
prek-head run identity --all-files	8.9 ± 0.3	8.7	9.8	1.00

✅ Performance improvement for prek run identity --all-files: 19.4800% faster