Unexpected backtrace when adding rustup component

Thanks to everyone working on this awesome tool! ❤️

Problem
In a nutshell:

Steps

1. Run rustup component add llvm-tools in your terminal of choice

Notes
My everyday configuration is having RUST_BACKTRACE set to 1. It is also the configuration used in the screenshot above.

However, as I was investigating this, I tried setting RUST_BACKTRACE to full, hoping to learn more.

But doing so instead made the backtrace disappear entirely!

Is it a known or intentional behaviour that upping the verbosity level of backtraces can produce the opposite effect (silencing them, in practice)?

Surely the panic behavior itself didn't change as the value of RUST_BACKTRACE changed. (Right?)

Thanks in advance, apologies if anything crucial is missing or if I posted this in the wrong section.

Output of rustup --version:

rustup 1.24.1 (a01bd6b0d 2021-04-27)

Output of rustup show:

Default host: x86_64-pc-windows-msvc
rustup home: C:\Users\WorstPractice.rustup

installed toolchains

stable-x86_64-pc-windows-msvc
nightly-x86_64-pc-windows-msvc (default)

active toolchain

nightly-x86_64-pc-windows-msvc (default)
rustc 1.54.0-nightly (5c0292654 2021-05-11)

Start by reproducing rustup component add llvm-tools on the reported Windows toolchain with RUST_BACKTRACE=1 and RUST_BACKTRACE=full, comparing the resulting output. The issue is done when the differing backtrace behavior is explained and the command no longer produces an unexpected or silently missing backtrace.