Constant WRAPPERS_PREAMBLE_HEADER 

const WRAPPERS_PREAMBLE_HEADER: &str = "# This file is generated by the miniextendr proc-macro during package build.
# Any manual changes will be overwritten.
#
# To regenerate: rebuild the package (R CMD INSTALL or devtools::install).
# nolint start
# nocov start

# Internal helper: re-raise a tagged Rust error/condition value as an R condition.
# Generated wrappers call this whenever `.Call()` returns a `rust_condition_value`.
# `.call_default` is the wrapper's `sys.call()` (or its `.mx_call`, the
# caller's call as written, for `#[miniextendr(noexport, call = caller)]` entry
# points, which honours a `.call` a helper passed on; an S3 method's frame,
# `environment()`, resolved to the generic's call here; NULL for a
# `call = none` wrapper), used as the fallback when the Rust panic payload
# didn't carry a captured call (e.g. lambda contexts that pass `.call = NULL`
# to `.Call`). For error/panic kinds `stop()` longjmps; for
# warning/message/condition the helper signals and returns invisible(NULL),
# which the wrapper's surrounding `return(...)` propagates as its result.
";

The comment block that opens the wrappers preamble, ahead of the .miniextendr_raise_condition binding, as written by write_r_wrappers_to_file.