The new static_assert message is great, there are some simple messages where an expansion isn't particularly helpful.

For example

constexpr auto is_gitlab = false;
constexpr auto is_weekend = false;

static_assert(is_gitlab or is_weekend);

will give us

<source>:4:1: error: static assertion failed due to requirement 'is_gitlab || is_weekend'
static_assert(is_gitlab or is_weekend);
^             ~~~~~~~~~~~~~~~~~~~~~~~
<source>:4:25: note: expression evaluates to 'false || false'
static_assert(is_gitlab or is_weekend);
              ~~~~~~~~~~^~~~~~~~~~~~~

The note isn't necessary, since the error implies that the expression will be false or false. I noticed that if we change the expression to a conjunction, we get a simpler message, so it looks like the machinery might already be present.

<source>:4:1: error: static assertion failed due to requirement 'is_gitlab'
static_assert(is_gitlab and is_weekend);
^             ~~~~~~~~~

We should---on a best effort basis---aim to eliminate expansions that don't add value to minimise user frustration (this will give us slightly more room to have longer diagnostics elsewhere).