Add a "fork" of musl as //fusl.

fusl/include/sys/ptrace.h

+#ifndef _SYS_PTRACE_H
+#define _SYS_PTRACE_H
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdint.h>
+
+#define PTRACE_TRACEME 0
+#define PT_TRACE_ME PTRACE_TRACEME
+
+#define PTRACE_PEEKTEXT 1
+#define PTRACE_PEEKDATA 2
+#define PTRACE_PEEKUSER 3
+#define PTRACE_POKETEXT 4
+#define PTRACE_POKEDATA 5
+#define PTRACE_POKEUSER 6
+#define PTRACE_CONT 7
+#define PTRACE_KILL 8
+#define PTRACE_SINGLESTEP 9
+#define PTRACE_GETREGS 12
+#define PTRACE_SETREGS 13
+#define PTRACE_GETFPREGS 14
+#define PTRACE_SETFPREGS 15
+#define PTRACE_ATTACH 16
+#define PTRACE_DETACH 17
+#define PTRACE_GETFPXREGS 18
+#define PTRACE_SETFPXREGS 19
+#define PTRACE_SYSCALL 24
+#define PTRACE_SETOPTIONS 0x4200
+#define PTRACE_GETEVENTMSG 0x4201
+#define PTRACE_GETSIGINFO 0x4202
+#define PTRACE_SETSIGINFO 0x4203
+#define PTRACE_GETREGSET 0x4204
+#define PTRACE_SETREGSET 0x4205
+#define PTRACE_SEIZE 0x4206
+#define PTRACE_INTERRUPT 0x4207
+#define PTRACE_LISTEN 0x4208
+#define PTRACE_PEEKSIGINFO 0x4209
+#define PTRACE_GETSIGMASK 0x420a
+#define PTRACE_SETSIGMASK 0x420b
+
+#define PT_READ_I PTRACE_PEEKTEXT
+#define PT_READ_D PTRACE_PEEKDATA
+#define PT_READ_U PTRACE_PEEKUSER
+#define PT_WRITE_I PTRACE_POKETEXT
+#define PT_WRITE_D PTRACE_POKEDATA
+#define PT_WRITE_U PTRACE_POKEUSER
+#define PT_CONTINUE PTRACE_CONT
+#define PT_KILL PTRACE_KILL
+#define PT_STEP PTRACE_SINGLESTEP
+#define PT_GETREGS PTRACE_GETREGS
+#define PT_SETREGS PTRACE_SETREGS
+#define PT_GETFPREGS PTRACE_GETFPREGS
+#define PT_SETFPREGS PTRACE_SETFPREGS
+#define PT_ATTACH PTRACE_ATTACH
+#define PT_DETACH PTRACE_DETACH
+#define PT_GETFPXREGS PTRACE_GETFPXREGS
+#define PT_SETFPXREGS PTRACE_SETFPXREGS
+#define PT_SYSCALL PTRACE_SYSCALL
+#define PT_SETOPTIONS PTRACE_SETOPTIONS
+#define PT_GETEVENTMSG PTRACE_GETEVENTMSG
+#define PT_GETSIGINFO PTRACE_GETSIGINFO
+#define PT_SETSIGINFO PTRACE_SETSIGINFO
+
+#define PTRACE_O_TRACESYSGOOD   0x00000001
+#define PTRACE_O_TRACEFORK      0x00000002
+#define PTRACE_O_TRACEVFORK     0x00000004
+#define PTRACE_O_TRACECLONE     0x00000008
+#define PTRACE_O_TRACEEXEC      0x00000010
+#define PTRACE_O_TRACEVFORKDONE 0x00000020
+#define PTRACE_O_TRACEEXIT      0x00000040
+#define PTRACE_O_TRACESECCOMP   0x00000080
+#define PTRACE_O_EXITKILL       0x00100000
+#define PTRACE_O_MASK           0x001000ff
+
+#define PTRACE_EVENT_FORK 1
+#define PTRACE_EVENT_VFORK 2
+#define PTRACE_EVENT_CLONE 3
+#define PTRACE_EVENT_EXEC 4
+#define PTRACE_EVENT_VFORK_DONE 5
+#define PTRACE_EVENT_EXIT 6
+#define PTRACE_EVENT_SECCOMP 7
+
+#define PTRACE_PEEKSIGINFO_SHARED 1
+
+struct ptrace_peeksiginfo_args {
+        uint64_t off;
+        uint32_t flags;
+        int32_t nr;
+};
+
+long ptrace(int, ...);
+
+#ifdef __cplusplus
+}
+#endif
+#endif