$ spack reindex
$ spack install re2c

$ spack -d install re2c
...
  Fetch: 0.02s.  Build: 1m 40.30s.  Total: 1m 40.32s.
[+] /Users/Adam/spack/opt/spack/darwin-catalina-x86_64/apple-clang-12.0.0/re2c-1.2.1-7eg6bjrpxpiackuur7ruknhsbjz2wikq
==> [2020-10-31-21:56:25.779818] NoSuchPatchError: Couldn't find patch for package builtin.graphviz with sha256: 99962eb1a491bbaa8afc6d8d238f3edb3b45badf1c1f9af026ed52c6c28d2d8a
==> [2020-10-31-21:56:25.780602] Error: Failed to install re2c due to NoSuchPatchError: Couldn't find patch for package builtin.graphviz with sha256: 99962eb1a491bbaa8afc6d8d238f3edb3b45badf1c1f9af026ed52c6c28d2d8a
==> [2020-10-31-21:56:25.780758] Flagging re2c as failed: Couldn't find patch for package builtin.graphviz with sha256: 99962eb1a491bbaa8afc6d8d238f3edb3b45badf1c1f9af026ed52c6c28d2d8a
==> [2020-10-31-21:56:25.788636] NoSuchPatchError: Couldn't find patch for package builtin.graphviz with sha256: 99962eb1a491bbaa8afc6d8d238f3edb3b45badf1c1f9af026ed52c6c28d2d8a
==> [2020-10-31-21:56:25.788763] Error: Couldn't find patch for package builtin.graphviz with sha256: 99962eb1a491bbaa8afc6d8d238f3edb3b45badf1c1f9af026ed52c6c28d2d8a
Traceback (most recent call last):
  File "/Users/Adam/spack/lib/spack/spack/main.py", line 762, in main
    return _invoke_command(command, parser, args, unknown)
  File "/Users/Adam/spack/lib/spack/spack/main.py", line 490, in _invoke_command
    return_val = command(parser, args)
  File "/Users/Adam/spack/lib/spack/spack/cmd/install.py", line 405, in install
    install_spec(args, kwargs, abstract, concrete)
  File "/Users/Adam/spack/lib/spack/spack/cmd/install.py", line 256, in install_spec
    spec.package.do_install(**kwargs)
  File "/Users/Adam/spack/lib/spack/spack/package.py", line 1602, in do_install
    builder.install(**kwargs)
  File "/Users/Adam/spack/lib/spack/spack/installer.py", line 1591, in install
    self._install_task(task, **kwargs)
  File "/Users/Adam/spack/lib/spack/spack/installer.py", line 1210, in _install_task
    explicit=explicit)
  File "/Users/Adam/spack/lib/spack/spack/database.py", line 120, in converter
    return function(self, spec_like, *args, **kwargs)
  File "/Users/Adam/spack/lib/spack/spack/database.py", line 1135, in add
    self._add(spec, directory_layout, explicit=explicit)
  File "/Users/Adam/spack/lib/spack/llnl/util/lock.py", line 584, in __exit__
    if self._exit(release_fn):
  File "/Users/Adam/spack/lib/spack/llnl/util/lock.py", line 605, in _exit
    return self._lock.release_write(release_fn)
  File "/Users/Adam/spack/lib/spack/llnl/util/lock.py", line 461, in release_write
    result = release_fn()
  File "/Users/Adam/spack/lib/spack/llnl/util/lock.py", line 578, in release_fn
    return self._release_fn(type, value, traceback)
  File "/Users/Adam/spack/lib/spack/spack/database.py", line 978, in _write
    self._write_to_file(f)
  File "/Users/Adam/spack/lib/spack/spack/database.py", line 613, in _write_to_file
    for k, v in self._data.items())
  File "/Users/Adam/spack/lib/spack/spack/database.py", line 613, in <genexpr>
    for k, v in self._data.items())
  File "/Users/Adam/spack/lib/spack/spack/database.py", line 212, in to_dict
    rec_dict.update({'spec': self.spec.node_dict_with_hashes()})
  File "/Users/Adam/spack/lib/spack/spack/spec.py", line 1654, in node_dict_with_hashes
    node[self.name]['full_hash'] = self.full_hash()
  File "/Users/Adam/spack/lib/spack/spack/spec.py", line 1464, in full_hash
    return self._cached_hash(ht.full_hash, length)
  File "/Users/Adam/spack/lib/spack/spack/spec.py", line 1431, in _cached_hash
    hash_string = self._spec_hash(hash)
  File "/Users/Adam/spack/lib/spack/spack/spec.py", line 1404, in _spec_hash
    node_dict = self.to_node_dict(hash=hash)
  File "/Users/Adam/spack/lib/spack/spack/spec.py", line 1562, in to_node_dict
    d['package_hash'] = self.package.content_hash()
  File "/Users/Adam/spack/lib/spack/spack/package.py", line 1437, in content_hash
    for p in self.spec.patches)
  File "/Users/Adam/spack/lib/spack/llnl/util/lang.py", line 197, in _memoized_function
    func.cache[args] = func(*args)
  File "/Users/Adam/spack/lib/spack/spack/spec.py", line 3090, in patches
    patch = index.patch_for_package(sha256, self.package)
  File "/Users/Adam/spack/lib/spack/spack/patch.py", line 350, in patch_for_package
    % (pkg.fullname, sha256))
spack.patch.NoSuchPatchError: Couldn't find patch for package builtin.graphviz with sha256: 99962eb1a491bbaa8afc6d8d238f3edb3b45badf1c1f9af026ed52c6c28d2d8a