def f():    def g(arg: int, /):        passf()$ python3.9 t2.pyTraceback (most recent call last):  File "/home/asottile/workspace/t2.py", line 5, in <module>    f()  File "/home/asottile/workspace/t2.py", line 2, in f    def g(arg: int, /):SystemError: no locals when loading 'int'Originally from this StackOverflow post:https://stackoverflow.com/q/59594494/812183

Looks as though annotations are using `LOAD_NAME` when they should probably use `LOAD_GLOBAL`?```$ diff -u <(python3.9 -m dis t2.py | sed 's/0x[a-f0-9]*/0xdeadbeef/g;s/t2\.py/FILENAME/g') <(python3.9 -m dis t3.py | sed 's/0x[a-f0-9]*/0xdeadbeef/g;s/t3\.py/FILENAME/g')--- /dev/fd/632020-01-04 16:34:27.372004436 -0800+++ /dev/fd/622020-01-04 16:34:27.372004436 -0800@@ -10,7 +10,7 @@              16 RETURN_VALUE  Disassembly of <code object f at 0xdeadbeef, file "FILENAME", line 1>:-  2           0 LOAD_NAME                0 (int)+  2           0 LOAD_GLOBAL              0 (int)               2 LOAD_CONST               1 (('arg',))               4 BUILD_CONST_KEY_MAP      1               6 LOAD_CONST               2 (<code object g at 0xdeadbeef, file "FILENAME", line 2>)```t3.py is the same as t2.py but without positional-only arguments

this triggers an assertion when run with debug enabled:$ gdb ./python GNU gdb (Ubuntu 8.1-0ubuntu3.2) 8.1.0.20180409-gitCopyright (C) 2018 Free Software Foundation, Inc.License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>This is free software: you are free to change and redistribute it.There is NO WARRANTY, to the extent permitted by law.  Type "show copying"and "show warranty" for details.This GDB was configured as "x86_64-linux-gnu".Type "show configuration" for configuration details.For bug reporting instructions, please see:<http://www.gnu.org/software/gdb/bugs/>.Find the GDB manual and other documentation resources online at:<http://www.gnu.org/software/gdb/documentation/>.For help, type "help".Type "apropos word" to search for commands related to "word"...Reading symbols from ./python...done.warning: File "/home/asottile/workspace/cpython/python-gdb.py" auto-loading has been declined by your `auto-load safe-path' set to "$debugdir:$datadir/auto-load".To enable execution of this file addadd-auto-load-safe-path /home/asottile/workspace/cpython/python-gdb.pyline to your configuration file "/home/asottile/.gdbinit".To completely disable this security protection addset auto-load safe-path /line to your configuration file "/home/asottile/.gdbinit".For more information about this security protection see the"Auto-loading safe path" section in the GDB manual.  E.g., run from the shell:info "(gdb)Auto-loading safe path"(gdb) run t2.pyStarting program: /home/asottile/workspace/cpython/python t2.py[Thread debugging using libthread_db enabled]Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".python:Python/compile.c:3545: compiler_nameop: Assertion `scope || PyUnicode_READ_CHAR(name, 0) == '_'' failed.Program received signal SIGABRT, Aborted.__GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:5151../sysdeps/unix/sysv/linux/raise.c: No such file or directory.(gdb) bt#0  __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:51#1  0x00007ffff7060801 in __GI_abort () at abort.c:79#2  0x00007ffff705039a in __assert_fail_base (    fmt=0x7ffff71d77d8 "%s%s%s:%u: %s%sAssertion `%s' failed.\n%n",assertion=assertion@entry=0x555555815190 "scope || PyUnicode_READ_CHAR(name, 0) == '_'",file=file@entry=0x555555814233 "Python/compile.c",line=line@entry=3545,function=function@entry=0x555555814180 <__PRETTY_FUNCTION__.17589> "compiler_nameop") at assert.c:92#3  0x00007ffff7050412 in __GI___assert_fail (assertion=assertion@entry=0x555555815190 "scope || PyUnicode_READ_CHAR(name, 0) == '_'",file=file@entry=0x555555814233 "Python/compile.c",line=line@entry=3545,function=function@entry=0x555555814180 <__PRETTY_FUNCTION__.17589> "compiler_nameop") at assert.c:101#4  0x000055555568e946 in compiler_nameop (c=0x7fffffffdb40,     name=<optimized out>, ctx=Load) atPython/compile.c:3545#5  0x000055555569020e in compiler_visit_expr1 (c=c@entry=0x7fffffffdb40,     e=0x555555b739d0) atPython/compile.c:5027#6  0x000055555569027f in compiler_visit_expr (c=0x7fffffffdb40,     e=<optimized out>) atPython/compile.c:5052#7  0x0000555555693570 in compiler_visit_argannotation (c=c@entry=0x7fffffffdb40, id=0x7ffff7f95d60, annotation=<optimized out>,names=names@entry=0x7ffff66217d0) atPython/compile.c:2045#8  0x000055555569363e in compiler_visit_argannotations (c=c@entry=0x7fffffffdb40, args=0x555555b739c0,names=names@entry=0x7ffff66217d0) atPython/compile.c:2066#9  0x00005555556936b2 in compiler_visit_annotations (c=c@entry=0x7fffffffdb40,args=args@entry=0x555555b73a28,returns=returns@entry=0x0) atPython/compile.c:2094#10 0x00005555556939fc in compiler_function (c=0x7fffffffdb40,     s=0x555555b73ab8,is_async=is_async@entry=0) atPython/compile.c:2214#11 0x0000555555693dad in compiler_visit_stmt (c=c@entry=0x7fffffffdb40,     s=0x555555b73ab8) atPython/compile.c:3332---Type <return> to continue, or q <return> to quit---#12 0x0000555555693b8f in compiler_function (c=0x7fffffffdb40,     s=<optimized out>,is_async=is_async@entry=0) atPython/compile.c:2238#13 0x0000555555693dad in compiler_visit_stmt (c=c@entry=0x7fffffffdb40,     s=0x555555b73b00) atPython/compile.c:3332#14 0x0000555555694022 in compiler_body (c=c@entry=0x7fffffffdb40,     stmts=0x555555b73960) atPython/compile.c:1816#15 0x0000555555694754 in compiler_mod (c=c@entry=0x7fffffffdb40,mod=mod@entry=0x555555b73c00) atPython/compile.c:1836#16 0x000055555569682b in PyAST_CompileObject (mod=mod@entry=0x555555b73c00,filename=filename@entry=0x7ffff662a7b0,flags=flags@entry=0x7fffffffddc0,optimize=optimize@entry=-1,arena=arena@entry=0x7ffff7e69640)    atPython/compile.c:364#17 0x00005555556c20cc in run_mod (mod=mod@entry=0x555555b73c00,filename=filename@entry=0x7ffff662a7b0,globals=globals@entry=0x7ffff7ecf3b0,locals=locals@entry=0x7ffff7ecf3b0,flags=flags@entry=0x7fffffffddc0,arena=arena@entry=0x7ffff7e69640)    atPython/pythonrun.c:1138#18 0x00005555556c530c in PyRun_FileExFlags (fp=fp@entry=0x555555b6d000,filename_str=filename_str@entry=0x7ffff7ecf720 "/home/asottile/workspace/cpython/t2.py",start=start@entry=257,globals=globals@entry=0x7ffff7ecf3b0,locals=locals@entry=0x7ffff7ecf3b0,closeit=closeit@entry=1,     flags=0x7fffffffddc0) atPython/pythonrun.c:1063#19 0x00005555556c56e6 in PyRun_SimpleFileExFlags (fp=fp@entry=0x555555b6d000,     filename=<optimized out>,filename@entry=0x7ffff7ecf720 "/home/asottile/workspace/cpython/t2.py",closeit=closeit@entry=1,flags=flags@entry=0x7fffffffddc0)    atPython/pythonrun.c:428#20 0x00005555556c58e9 in PyRun_AnyFileExFlags (fp=fp@entry=0x555555b6d000,     filename=0x7ffff7ecf720 "/home/asottile/workspace/cpython/t2.py",closeit=closeit@entry=1,flags=flags@entry=0x7fffffffddc0)    atPython/pythonrun.c:86#21 0x00005555555aceca in pymain_run_file (config=config@entry=0x555555b2f190,cf=cf@entry=0x7fffffffddc0) atModules/main.c:369#22 0x00005555555ad698 in pymain_run_python (exitcode=exitcode@entry=0x7fffffffddf4) atModules/main.c:553#23 0x00005555555ad703 in Py_RunMain () atModules/main.c:632#24 0x00005555555ad77d in pymain_main (args=args@entry=0x7fffffffde50)    atModules/main.c:662#25 0x00005555555ad843 in Py_BytesMain (argc=<optimized out>,     argv=<optimized out>) atModules/main.c:686---Type <return> to continue, or q <return> to quit---#26 0x00005555555ac053 in main (argc=<optimized out>, argv=<optimized out>)    at ./Programs/python.c:16

Thanks, Anthony, for the quick fix and the investigation! :)