--- a/dev-lang/rust/rust-1.59.0.ebuild	2022-03-04 08:30:13.935008024 +0100
+++ b/dev-lang/rust/rust-1.59.0.ebuild	2022-03-04 08:32:41.890009406 +0100
@@ -41,7 +41,7 @@
 
 LICENSE="|| ( MIT Apache-2.0 ) BSD-1 BSD-2 BSD-4 UoI-NCSA"
 
-IUSE="clippy cpu_flags_x86_sse2 debug dist doc miri nightly parallel-compiler rls rustfmt rust-src system-bootstrap system-llvm test wasm ${ALL_LLVM_TARGETS[*]}"
+IUSE="clippy cpu_flags_x86_sse2 debug dist doc miri nightly parallel-compiler rls rustfmt rust-src system-bootstrap system-llvm test wasm llvm-libunwind ${ALL_LLVM_TARGETS[*]}"
 
 # Please keep the LLVM dependency block separate. Since LLVM is slotted,
 # we need to *really* make sure we're not pulling more than one slot
@@ -107,6 +107,7 @@
 	dev-libs/openssl:0=
 	elibc_musl? ( sys-libs/libunwind:= )
 	system-llvm? ( ${LLVM_DEPEND} )
+	llvm-libunwind? ( sys-libs/llvm-libunwind )
 "
 
 # we need to block older versions due to layout changes.
@@ -383,6 +384,7 @@
 		deny-warnings = $(usex wasm $(usex doc false true) true)
 		backtrace-on-ice = true
 		jemalloc = false
+		llvm-libunwind = "$(usex llvm-libunwind in-tree no)"
 		[dist]
 		src-tarball = false
 		compression-formats = ["xz"]