[librsvg/cargo-c: 65/66] configure.ac: check for cargo-cbuild

[Federico Mena Quintero <federico src gnome org>]

commit 7fb0a93ea9dfa5f781260aadd371421507aec56b
Author: Federico Mena Quintero <federico gnome org>
Date:   Tue Jun 22 16:56:49 2021 -0500

    configure.ac: check for cargo-cbuild

 configure.ac | 4 ++++
 1 file changed, 4 insertions(+)
---
diff --git a/configure.ac b/configure.ac
index f08b82ba..a679014a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -101,6 +101,10 @@ AC_CHECK_TOOL(RUSTC, [rustc], [no])
 AS_IF(test x$RUSTC = xno,
     AC_MSG_ERROR([rustc is required.  Please install the Rust toolchain from https://www.rust-lang.org/])
 )
+AC_CHECK_TOOL(CARGO_C, [cargo-cbuild], [no])
+AS_IF(test x$CARGO_C = xno,
+    AC_MSG_ERROR([cargo-c is required.  Please install it from https://github.com/lu-zero/cargo-c/])
+)
 
 dnl MSRV - Minimum Supported Rust Version
 dnl If you change this, please update COMPILING.md