fix(rust): Try and find why our toolchain keeps getting re-installed

earthly/rust/Earthfile

@@ -112,13 +112,19 @@ rust-base-plus-tools:
 installer:
     FROM +rust-base-plus-tools
 
+    RUN rustup show
+
     # Call +INIT before copying the source file to avoid installing dependencies every time source code changes. 
     # This parametrization will be used in future calls to functions of the library
     # Init using the common cat-ci cache prefix.
     DO rust+INIT --keep_fingerprints=true
 
+    RUN rustup show
+
     DO rust+SET_CACHE_MOUNTS_ENV
 
+    RUN rustup show
+
     # Install the default cargo config, and ensure its in the cached CARGO_HOME as well.
     COPY stdcfgs/cargo_config.toml $CARGO_INSTALL_ROOT/config.toml
     DO +EXECUTE --cmd="cp $CARGO_INSTALL_ROOT/config.toml $CARGO_HOME/config.toml"
@@ -134,6 +140,8 @@ installer:
     # This is to enforce consistent compiler and tool configuration on local setup and CI builds.
     COPY --dir stdcfgs /stdcfgs
 
+    RUN rustup show
+
 # Builds all the rust-base targets for each supported DOCKER architecture.
 # Currently only used for multi-platform cross build testing.
 # This will ONLY work if you have `qemu` properly setup on linux and `rosetta` for
@@ -270,10 +278,14 @@ SETUP:
     FUNCTION
     FROM +installer
 
+    RUN rustup show
+
     ARG toolchain=./rust-toolchain.toml 
 
     # Copy our toolchain dependency.
     COPY $toolchain ./rust-toolchain.toml
 
+    RUN rustup show
+
     # Toolchain MUST be the same as vendored, and if it is the toolchain is
     # already installed.