[OE-core] [PATCH 1/2] ruby: configure mis-detects isnan/isinf on musl

[André Draszik]

From: André Draszik <andre.draszik at jci.com>

The configure script does not detect isnan/isinf as macros
as is the case in musl.

Help it by providing the correct result via
CACHED_CONFIGUREVARS.

Signed-off-by: André Draszik <andre.draszik at jci.com>
---
 meta/recipes-devtools/ruby/ruby_2.5.5.bb | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/meta/recipes-devtools/ruby/ruby_2.5.5.bb b/meta/recipes-devtools/ruby/ruby_2.5.5.bb
index 8ad59a7657..fdd3852a78 100644
--- a/meta/recipes-devtools/ruby/ruby_2.5.5.bb
+++ b/meta/recipes-devtools/ruby/ruby_2.5.5.bb
@@ -32,6 +32,9 @@ EXTRA_OECONF = "\
     --with-pkg-config=pkg-config \
 "
 
+# the configure script does not detect isnan/isinf as macros
+CACHED_CONFIGUREVARS_libc-musl += "ac_cv_func_isnan=yes ac_cv_func_isinf=yes"
+
 do_install() {
     oe_runmake 'DESTDIR=${D}' install
 }
-- 
2.23.0.rc1