Use the new way to set debuginfo level during build

rust-cargo-c.spec

@@ -1,10 +1,7 @@
 # Generated by rust2rpm 20
 %bcond_without check
 
-# work around RUSTFLAGS no longer being set in .cargo/config with rust2rpm 21
+%global rustflags_debuginfo 1
-# https://pagure.io/fedora-rust/rust2rpm/issue/181
-%global __cargo %(echo %__cargo | sed "s/debuginfo=2/debuginfo=1/")
-%global debug_package %{nil}
 
 %global crate cargo-c
 %global upstream_version 0.9.7+cargo-0.59
@@ -25,7 +22,7 @@ Patch0:         cargo-c-fix-metadata.diff
 
 ExclusiveArch:  %{rust_arches}
 
-BuildRequires:  rust-packaging
+BuildRequires:  rust-packaging >= 21-2
 
 %global _description %{expand:
 Helper program to build and install c-like libraries.}
@@ -84,8 +81,6 @@ use the "default" feature of the "%{crate}" crate.
 %prep
 %autosetup -n %{crate}-%{upstream_version} -p1
 %cargo_prep
-# drop debuginfo verbosity in an attempt to fix armv7hl OOM problems
-sed -i "s/debuginfo=2/debuginfo=1/" .cargo/config
 
 %generate_buildrequires
 %cargo_generate_buildrequires