BuildTimer

Measure command durations and compare them with previous local runs.

BuildTimer is a small, Linux-first Rust CLI for measuring how long build, test, and other terminal commands take and comparing the result with the previous local run of the same command.

It is local-only: no telemetry, cloud service, account, server, or network backend is involved.

Status

BuildTimer v0.1.0 is available as the first public release.

A prebuilt Linux x86_64 binary and SHA-256 checksum are available on the GitHub Releases page.

What it does

buildtimer -- cargo build --release

BuildTimer starts the wrapped executable directly, waits for it to finish, prints the elapsed time, stores a local history entry, and compares the result with the previous matching command.

Example output:

BuildTimer: 12.438 s
Previous: 13.102 s -> 12.438 s (664 ms faster, 5.1%)

The wrapped process exit code is returned by BuildTimer unchanged. If the process is terminated by a Unix signal, BuildTimer uses the conventional 128 + signal process exit status.

Install on Linux x86_64

Download these files from the v0.1.0 release:

• buildtimer-linux-x86_64
• buildtimer-linux-x86_64.sha256

Verify and run:

sha256sum -c buildtimer-linux-x86_64.sha256
chmod +x buildtimer-linux-x86_64
./buildtimer-linux-x86_64 --version

You can optionally rename the binary to buildtimer and place it somewhere on your PATH, such as ~/.local/bin.

Commands

Run and time a command:

buildtimer -- cargo test
buildtimer -- cargo build --release
buildtimer -- make -j8

Show recent history:

buildtimer history

Clear local history:

buildtimer clear

Direct process execution

BuildTimer does not execute wrapped commands through sh -c, bash -c, or another shell. The executable and argument vector are passed directly through Rust's std::process::Command API.

That means shell interpolation is intentionally not performed by BuildTimer. For example, $TOKEN, pipes, redirections, globs, and command substitution are not expanded unless you explicitly choose a shell as the wrapped executable yourself.

Local history and privacy

History is stored locally at:

$XDG_DATA_HOME/buildtimer/history.json

or, when XDG_DATA_HOME is unset:

~/.local/share/buildtimer/history.json

The file contains only BuildTimer history metadata such as the sanitized command display, duration, and Unix timestamp. BuildTimer never enumerates or stores the process environment.

Before persistence, BuildTimer redacts common secret-bearing arguments such as:

TOKEN=value          -> TOKEN=<redacted>
--password value     -> --password <redacted>
--api-key=value      -> --api-key=<redacted>
https://user:pass@... -> https://<redacted>@...

Environment-style NAME=value arguments are always persisted with the value redacted. History is capped at the most recent 500 entries. On Unix, the BuildTimer data directory is set to mode 0700 and the history file to mode 0600.

Command start failures

If a wrapped executable cannot be started, BuildTimer reports the operating-system error and does not write a history entry.

Common Unix-compatible return codes are used:

• 127 when the executable cannot be found
• 126 when permission is denied
• 1 for other process-start errors

Build from source

Requirements:

• Rust 1.80 or newer
• Linux is the primary supported platform for v0.1.0

git clone https://github.com/BLCCoreStudio/BuildTimer.git
cd BuildTimer
cargo build --release --locked
./target/release/buildtimer --version

For local installation during development:

cargo install --path . --locked

Development checks

The CI workflow runs the same required checks on pull requests and on main:

cargo fmt --all -- --check
cargo clippy --locked --all-targets --all-features -- -D warnings
cargo test --locked --all-features

See CONTRIBUTING.md before sending changes and SECURITY.md for vulnerability reporting guidance.

License

BuildTimer is licensed under the MIT License.

Built by BLC Core Studio.