How to get path to the external directory in Bazel?

Question

This page describes the various folders and symlinks that Bazel generates.

I am interested in this one:

  external/                       <== The directory that remote repositories are
                                      downloaded/symlinked into.

I would also like to get two things:

1. The absolute path to this folder
2. The path of the symlink used to access this folder from the workspace root.

I think that (2) follows this pattern: bazel-my-project/external

How can I get these paths from the Bazel CLI?

Answer 1

Use $(bazel info output_base)/external . $(bazel info execution_root)/external may not always work, since the execution root can be ephemeral as a symlink tree. The latter just contains symlinks to the former:

$ ls -al $(bazelisk info output_base)/execroot/__main__/external
total 44
drwxr-x--- 2 jingwen primarygroup 4096 Jul  6 12:51 .
drwxr-x--- 5 jingwen primarygroup 4096 Jul  6 12:51 ..
lrwxrwxrwx 1 jingwen primarygroup  112 Jul  6 12:51 bazel_tools -> /home/jingwen/.cache/bazel/_bazel_jingwen/e375750af2fc236b3604a3cb5bfe4b91/external/bazel_tools
lrwxrwxrwx 1 jingwen primarygroup  116 Jul  6 12:51 local_config_cc -> /home/jingwen/.cache/bazel/_bazel_jingwen/e375750af2fc236b3604a3cb5bfe4b91/external/local_config_cc
lrwxrwxrwx 1 jingwen primarygroup  110 Jul  6 12:51 local_jdk -> /home/jingwen/.cache/bazel/_bazel_jingwen/e375750af2fc236b3604a3cb5bfe4b91/external/local_jdk
lrwxrwxrwx 1 jingwen primarygroup  106 Jul  6 12:51 maven -> /home/jingwen/.cache/bazel/_bazel_jingwen/e375750af2fc236b3604a3cb5bfe4b91/external/maven
lrwxrwxrwx 1 jingwen primarygroup  110 Jul  6 12:51 platforms -> /home/jingwen/.cache/bazel/_bazel_jingwen/e375750af2fc236b3604a3cb5bfe4b91/external/platforms
lrwxrwxrwx 1 jingwen primarygroup  122 Jul  6 12:51 remote_coverage_tools -> /home/jingwen/.cache/bazel/_bazel_jingwen/e375750af2fc236b3604a3cb5bfe4b91/external/remote_coverage_tools
lrwxrwxrwx 1 jingwen primarygroup  118 Jul  6 12:51 remote_java_tools -> /home/jingwen/.cache/bazel/_bazel_jingwen/e375750af2fc236b3604a3cb5bfe4b91/external/remote_java_tools
lrwxrwxrwx 1 jingwen primarygroup  124 Jul  6 12:51 remote_java_tools_linux -> /home/jingwen/.cache/bazel/_bazel_jingwen/e375750af2fc236b3604a3cb5bfe4b91/external/remote_java_tools_linux
lrwxrwxrwx 1 jingwen primarygroup  118 Jul  6 12:51 remotejdk11_linux -> /home/jingwen/.cache/bazel/_bazel_jingwen/e375750af2fc236b3604a3cb5bfe4b91/external/remotejdk11_linux

If you just want to rely on the workspace symlinks, you can use readlink on the bazel-out symlink:

$ realpath $(readlink -f bazel-out)/../../../external
/home/jingwen/.cache/bazel/_bazel_jingwen/e375750af2fc236b3604a3cb5bfe4b91/external