docs: build.rst: Document tested version of Nightly Rust, actually

IDK why the dates disagree, but they do.

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>

diff --git a/docs/build.rst b/docs/build.rst
index 5b82cb6fa0d65665f363f9d6e9a03a0895029bf3..19ba2050f0b4c3d85e54629a0c824f4e6b0f77d8 100644 (file)
--- a/docs/build.rst
+++ b/docs/build.rst
@@ -50,7 +50,7 @@ Setup
    version of Otter you have.  The following is known to work with
    Otter 0.7.1::
 
-     rustup default nightly-2021-06-07
+     rustup default nightly-2021-06-08 # downloads e4a603270 2021-06-07
 
    **If you just want to run the otter cli client over ssh to an existing server, or edit and preview the shape libraries (ie the piece shapes) you can stop here.**