Python toolchains in rules_python
Blog post from Aspect Build
Bazel aims to ensure repeatable and deterministic builds by declaring a hermetic build environment, where all tools used are specified with pinned versions, allowing consistent results across different machines and times. However, this consistency has been challenging for Python due to varying interpreter versions in different environments. The Aspect team has addressed this issue by introducing toolchain support in the latest 0.7.0 release of rules_python, enabling developers to use Bazel's toolchain system to discover and utilize the correct Python version automatically. The approach involves specifying the Python version and utilizing a workaround to load the resolved interpreter for repository rules, which execute before toolchain resolution. This advancement, facilitated by contributions from the community, is expected to enhance build reliability and consistency for Python projects using Bazel.