On Ubuntu from a program (specifically Python script) executed in a given directory with an active Rust toolchain I want to lookup the path to
libstd-<hash>.so of the active toolchain. In the given directory there resides a
rust-toolchain file which contains a toolchain definition.
When the Python script is executed with
rustup run <name of toolchain>, the environment variables are set and I should be able to lookup the corresponding
libstd with the help of
RUSTUP_TOOLCHAIN from within the Python script.
However, if the active toolchain is not defined by a preceding
rustup run, but by
rust-toolchain or by
rustup override set etc. (following the precedence rules), there are no environment variables set for the active toolchain which I could use from within the Python script. How can I lookup look up the path to the corresponding
libstd (from within the Python script) in this case? Is there something like
rustup run active ... to let rustup configure the environment for the active toolchain in the current directory?