Fix skip_build

Signed-off-by: Igor Gnatenko <ignatenkobrain@fedoraproject.org>

rust-ryu.spec

@@ -6,7 +6,7 @@
 
 Name:           rust-%{crate}
 Version:        0.2.8
-Release:        2%{?dist}
+Release:        3%{?dist}
 Summary:        Fast floating point to string conversion
 
 # Upstream license specification: Apache-2.0 OR BSL-1.0
@@ -20,10 +20,12 @@ BuildArch:      noarch
 %endif
 
 BuildRequires:  rust-packaging
+%if ! %{__cargo_skip_build}
 %if %{with check}
 BuildRequires:  (crate(num_cpus/default) >= 1.8.0 with crate(num_cpus/default) < 2.0.0)
 BuildRequires:  (crate(rand/default) >= 0.5.0 with crate(rand/default) < 0.6.0)
 %endif
+%endif
 
 %global _description %{expand:
 Fast floating point to string conversion.}
@@ -96,6 +98,9 @@ which use "small" feature of "%{crate}" crate.
 %endif
 
 %changelog
+* Sun Jun 09 12:24:37 CEST 2019 Igor Gnatenko <ignatenkobrain@fedoraproject.org> - 0.2.8-3
+- Fix skip_build
+
 * Sun Jun 09 11:10:21 CEST 2019 Igor Gnatenko <ignatenkobrain@fedoraproject.org> - 0.2.8-2
 - Regenerate