Fix test, add clarification for base_image used in conjunction with c…

…aching

.github/workflows/advanced-example.yml

@@ -59,6 +59,8 @@ jobs:
           # builds don't have to re-install them. The image layer is cached
           # publicly in your project's package repository, so it is vital that
           # no secrets are present in the container state or logs.
+          # In this workflow, the only none step using a base_image is Ubuntu, 
+          # so update apt without checking the acutal base_image value.
           install: |
             case "${{ matrix.distro }}" in
               ubuntu*|jessie|stretch|buster)
@@ -76,6 +78,9 @@ jobs:
               archarm*)
                 pacman -Syyu --noconfirm
                 pacman -S git which --noconfirm
+              none)
+                apt-get update -q -y
+                apt-get install -q -y git
             esac
 
           # Produce a binary artifact and place it in the mounted volume

README.md

@@ -20,7 +20,7 @@ The action also accepts some optional input parameters:
 * `dockerRunArgs`: Additional arguments to pass to `docker run`, such as volume mappings. See [`docker run` documentation](https://docs.docker.com/engine/reference/commandline/run).
 * `setup`: Shell commands to execute on the host before running the container, such as creating directories for volume mappings.
 * `install`: Shell commands to execute in the container as part of `docker build`, such as installing dependencies. This speeds up subsequent builds if `githubToken` is also used, but note that the image layer will be publicly available in your projects GitHub Package Registry, so make sure the resulting image does not have any secrets cached in logs or state.
-* `base_image`: Specify a custom base image, such as [busybox](https://hub.docker.com/_/busybox), `arch` and `distro` should be set to `none` in this case. This will allow you to chose direcly the image that will be used in the *FROM* clause of the internal docker container without needing to create a Dockerfile.arch.distro for a specific arch/distro pair. For more detials, see [PR #103](https://github.com/uraimo/run-on-arch-action/pull/103#issuecomment-1363810049).
+* `base_image`: Specify a custom base image, such as [busybox](https://hub.docker.com/_/busybox), `arch` and `distro` should be set to `none` in this case. This will allow you to chose direcly the image that will be used in the *FROM* clause of the internal docker container without needing to create a Dockerfile.arch.distro for a specific arch/distro pair. For more detials, see [PR #103](https://github.com/uraimo/run-on-arch-action/pull/103#issuecomment-1363810049). Known limitation: Only one base_image configuration for each workflow if you use GitHub images caching.
 
 ### Basic example