[gobject-introspection/docs-cross-launcher] docs: Document GI_CROSS_LAUNCHER envvar

[Emmanuele Bassi <ebassi src gnome org>]

commit 5fe9ab9653dcceea05dc97891f0bbb3fd4cc1d77
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Wed Sep 4 12:04:43 2019 +0100

    docs: Document GI_CROSS_LAUNCHER envvar
    
    The g-ir-scanner man page should include a mention of the
    GI_CROSS_LAUNCHER environment variable.

 docs/g-ir-scanner.1 | 4 ++++
 1 file changed, 4 insertions(+)
---
diff --git a/docs/g-ir-scanner.1 b/docs/g-ir-scanner.1
index c890291e..528bed5c 100644
--- a/docs/g-ir-scanner.1
+++ b/docs/g-ir-scanner.1
@@ -168,6 +168,10 @@ terminates.
 The variable \fBGI_HOST_OS\fP can be used to control the OS name on the host
 that runs the scanner. It has the same semantics as the Python \fBos.name\fP
 property.
+.sp
+The variable \fBGI_CROSS_LAUNCHER\fP can be used to wrap the GType introspection
+binary generated by g\-ir\-scanner before executing it. It is useful when
+generating introspection data in a cross-compilation environment.
 .SH BUGS
 .sp
 Report bugs at \fI\%https://gitlab.gnome.org/GNOME/gobject\-introspection/issues\fP