| commit | 48631eab923a0a04c27320253dd770a2f545eed7 | [log] [tgz] |
|---|---|---|
| author | Klaus Aehlig <aehlig@google.com> | Wed Mar 22 17:39:10 2017 +0000 |
| committer | Yue Gan <yueg@google.com> | Thu Mar 23 09:49:34 2017 +0000 |
| tree | 094492ff357767dae301a449407c1736158c8bdb | |
| parent | e3ccf8fe9fc1cb1922a55f923398f8064bf1bd04 [diff] |
Honor SOURCE_DATE_EPOCH in bootstrapping Currently, a stamped bazel binary contains the actual timestamp at build time. This means, that building bazel we either include no version information at all, or the binary contains a not reproducible time stamp. Both are not acceptable from the point of view of a downstream maintainer of a bazel package, where the requirement is that the package be reproducible, but the binary still provide sensible version information. Fortunately, there is a suggested standard to solve this problem taking the "current time" from the SOURCE_DATE_EPOCH environment variable, if set, rather than the actual time. See https://reproducible-builds.org/specs/source-date-epoch/. Honor this proposed standard, so that bazel can reasonably be packaged downstream. See issue #2240. Note that we only use the environment variable in our bootstrap script; for bazel itself we communicate that information via an appropriate option. -- Change-Id: I55409a117285b9a3446421179c20f4e8c59088f8 Reviewed-on: https://cr.bazel.build/9467 PiperOrigin-RevId: 150896326 MOS_MIGRATED_REVID=150896326
{Fast, Correct} - Choose two
Bazel is a build tool that builds code quickly and reliably. It is used to build the majority of Google‘s software, and thus it has been designed to handle build problems present in Google’s development environment, including:
A massive, shared code repository, in which all software is built from source. Bazel has been built for speed, using both caching and parallelism to achieve this. Bazel is critical to Google's ability to continue to scale its software development practices as the company grows.
An emphasis on automated testing and releases. Bazel has been built for correctness and reproducibility, meaning that a build performed on a continuous build machine or in a release pipeline will generate bitwise-identical outputs to those generated on a developer's machine.
Language and platform diversity. Bazel's architecture is general enough to support many different programming languages within Google, and can be used to build both client and server software targeting multiple architectures from the same underlying codebase.
Find more background about Bazel in our FAQ.