examples: specify rustfmt nightly using a $() construct
This is ugly, but it's how we have to configure rustfmt for now as we
require nightly rustfmt.
Differential Revision: https://phab.mercurial-scm.org/D7812
--- a/contrib/examples/fix.hgrc Sat Dec 07 13:13:48 2019 -0800
+++ b/contrib/examples/fix.hgrc Wed Jan 08 14:37:01 2020 -0500
@@ -2,7 +2,7 @@
clang-format:command = clang-format --style file
clang-format:pattern = set:(**.c or **.cc or **.h) and not "include:contrib/clang-format-ignorelist"
-rustfmt:command = rustfmt
+rustfmt:command = $(rustup which --toolchain nightly rustfmt)
rustfmt:pattern = set:**.rs
black:command = black --config=black.toml -