regression on -current with rust

rust doesn't build anymore in -current:
----------------------
Hmm... Looks like a unified diff to me...
The text leading up to this was:
--------------------------
|--- ./compiler/rustc_llvm/build.rs.orig 2020-11-16 08:01:53.000000000 -0600
|+++ ./compiler/rustc_llvm/build.rs 2020-11-19 13:46:21.222785372 -0600
--------------------------
patching file compiler/rustc_llvm/build.rs
Using Plan A...
Hunk #1 succeeded at 218 (offset -16 lines).
done
extracting /tmp/rustc-1.54.0-src/build/cache/2021-06-17/rust-std-1.53.0-x86_64-unknown-linux-gnu.tar.xz
Traceback (most recent call last):
File "/tmp/rustc-1.54.0-src/./x.py", line 27, in <module>
bootstrap.main()
File "/tmp/rustc-1.54.0-src/src/bootstrap/bootstrap.py", line 1195, in main
bootstrap(help_triggered)
File "/tmp/rustc-1.54.0-src/src/bootstrap/bootstrap.py", line 1161, in bootstrap
build.download_toolchain()
File "/tmp/rustc-1.54.0-src/src/bootstrap/bootstrap.py", line 413, in download_toolchain
self._download_component_helper(filename, pattern, tarball_suffix, stage0)
File "/tmp/rustc-1.54.0-src/src/bootstrap/bootstrap.py", line 527, in _download_component_helper
unpack(tarball, tarball_suffix, self.bin_root(stage0), match=pattern, verbose=self.verbose)
File "/tmp/rustc-1.54.0-src/src/bootstrap/bootstrap.py", line 122, in unpack
for member in tar.getnames():
File "/usr/lib64/python3.9/tarfile.py", line 1807, in getnames
return [tarinfo.name for tarinfo in self.getmembers()]
File "/usr/lib64/python3.9/tarfile.py", line 1799, in getmembers
self._load() # all members, we first have to
File "/usr/lib64/python3.9/tarfile.py", line 2388, in _load
tarinfo = self.next()
File "/usr/lib64/python3.9/tarfile.py", line 2319, in next
self.fileobj.seek(self.offset - 1)
File "/usr/lib64/python3.9/lzma.py", line 261, in seek
return self._buffer.seek(offset, whence)
File "/usr/lib64/python3.9/_compression.py", line 143, in seek
data = self.read(min(io.DEFAULT_BUFFER_SIZE, offset))
File "/usr/lib64/python3.9/_compression.py", line 99, in read
raise EOFError("Compressed file ended before the "
EOFError: Compressed file ended before the end-of-stream marker was reached
----------------------------------