Building wheel for twofish (setup.py) ... error
  ERROR: Command errored out with exit status 1:
   command: /opt/conda/bin/python3 -u -c 'import io, os, sys, setuptools, tokenize; sys.argv[0] = '"'"'/tmp/pip-install-mjpfyvnb/twofish_391887dcf3854563b11eddc863288449/setup.py'"'"'; __file__='"'"'/tmp/pip-install-mjpfyvnb/twofish_391887dcf3854563b11eddc863288449/setup.py'"'"';f = getattr(tokenize, '"'"'open'"'"', open)(__file__) if os.path.exists(__file__) else io.StringIO('"'"'from setuptools import setup; setup()'"'"');code = f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' bdist_wheel -d /tmp/pip-wheel-ss34cwr8
       cwd: /tmp/pip-install-mjpfyvnb/twofish_391887dcf3854563b11eddc863288449/
  Complete output (60 lines):
  running bdist_wheel
  running build
  running build_py
  creating build
  creating build/lib.linux-x86_64-3.8
  copying twofish.py -> build/lib.linux-x86_64-3.8
  running build_ext
  building '_twofish' extension
  creating build/temp.linux-x86_64-3.8
  creating build/temp.linux-x86_64-3.8/twofish-0.3
  gcc -pthread -B /opt/conda/compiler_compat -Wl,--sysroot=/ -Wsign-compare -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes -fPIC -Itwofish-0.3 -I/opt/conda/include/python3.8 -c twofish-0.3/twofish.c -o build/temp.linux-x86_64-3.8/twofish-0.3/twofish.o
  In file included from twofish-0.3/twofish.c:174:
  twofish-0.3/twofish.h:86:1: warning: function declaration isn't a prototype [-Wstrict-prototypes]
   extern void Twofish_initialise();
   ^~~~~~
  twofish-0.3/twofish.c:479:13: warning: function declaration isn't a prototype [-Wstrict-prototypes]
   static void test_platform()
               ^~~~~~~~~~~~~
  twofish-0.3/twofish.c:658:13: warning: function declaration isn't a prototype [-Wstrict-prototypes]
   static void test_vectors()
               ^~~~~~~~~~~~
  twofish-0.3/twofish.c:794:13: warning: function declaration isn't a prototype [-Wstrict-prototypes]
   static void test_sequences()
               ^~~~~~~~~~~~~~
  twofish-0.3/twofish.c:827:13: warning: function declaration isn't a prototype [-Wstrict-prototypes]
   static void test_odd_sized_keys()
               ^~~~~~~~~~~~~~~~~~~
  twofish-0.3/twofish.c:885:13: warning: function declaration isn't a prototype [-Wstrict-prototypes]
   static void self_test()
               ^~~~~~~~~
  twofish-0.3/twofish.c:999:13: warning: function declaration isn't a prototype [-Wstrict-prototypes]
   static void initialise_q_boxes() {
               ^~~~~~~~~~~~~~~~~~
  twofish-0.3/twofish.c:1043:13: warning: function declaration isn't a prototype [-Wstrict-prototypes]
   static void initialise_mds_tables()
               ^~~~~~~~~~~~~~~~~~~~~
  twofish-0.3/twofish.c:1231:6: warning: function declaration isn't a prototype [-Wstrict-prototypes]
   void Twofish_initialise()
        ^~~~~~~~~~~~~~~~~~
  gcc -pthread -B /opt/conda/compiler_compat -Wl,--sysroot=/ -Wsign-compare -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes -fPIC -Itwofish-0.3 -I/opt/conda/include/python3.8 -c twofish.c -o build/temp.linux-x86_64-3.8/twofish.o
  In file included from twofish.c:12:
  twofish-0.3/twofish.h:86:1: warning: function declaration isn't a prototype [-Wstrict-prototypes]
   extern void Twofish_initialise();
   ^~~~~~
  twofish.c:25:17: warning: function declaration isn't a prototype [-Wstrict-prototypes]
   DL_EXPORT(void) exp_Twofish_initialise() {
                   ^~~~~~~~~~~~~~~~~~~~~~
  twofish.c: In function 'init_twofish':
  twofish.c:45:1: warning: control reaches end of non-void function [-Wreturn-type]
   PyMODINIT_FUNC init_twofish(void) { }
   ^~~~~~~~~~~~~~
  twofish.c: In function 'PyInit__twofish':
  twofish.c:46:1: warning: control reaches end of non-void function [-Wreturn-type]
   PyMODINIT_FUNC PyInit__twofish(void) { }
   ^~~~~~~~~~~~~~
  gcc -pthread -shared -B /opt/conda/compiler_compat -L/opt/conda/lib -Wl,-rpath=/opt/conda/lib -Wl,--no-as-needed -Wl,--sysroot=/ build/temp.linux-x86_64-3.8/twofish-0.3/twofish.o build/temp.linux-x86_64-3.8/twofish.o -o build/lib.linux-x86_64-3.8/_twofish.cpython-38-x86_64-linux-gnu.so
  /opt/conda/compiler_compat/ld: cannot find /lib64/libpthread.so.0
  /opt/conda/compiler_compat/ld: cannot find /usr/lib64/libpthread_nonshared.a
  collect2: error: ld returned 1 exit status
  error: command 'gcc' failed with exit status 1
  ----------------------------------------
  ERROR: Failed building wheel for twofish