reverse-next in an async function in rust leads to an error `Probable previous-to-duplicated-state ..`

I build this program (I use a project where this is src/main.rs)

async fn a() {
    println!("a");
}

async fn b() {
    a().await;
    println!("next");
}

#[async_std::main]
async fn main() {
    b().await;
}

cargo file is

[package]
name = "async_rs"
version = "0.1.0"
authors = ["Alexander Ivanov <alehander42@gmail.com>"]
edition = "2018"

# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

[dependencies]
futures = "0.3.15"
async-std = {version = "1.9.0", features = ["attributes"] }

I build, record and replay:

cargo build
rr record target/debug/async_rs
rr replay

in rr I do

b async_rs::b::{{closure}}
# > Breakpoint 1 at 0x5570a6f99311: file src/main.rs, line 5.
c
# > Continuing.
# > [New Thread 347318.347319]
# > [New Thread 347318.347320]
# > 
# > Thread 1 hit Breakpoint 1, async_rs::b::{{closure}} () at src/main.rs:5
# > 5	async fn b() {
n
# > 6	    a().await;
rn # here i expect to go back normally
# but i get
Probable previous-to-duplicated-state at 313:{time:397,ticks:147361,st:7,regs:Printing register file:
rax:0x7ffebfb3a330
rbx:0x7ffebfb3b6e0
rcx:0x7ffebfb3a330
rdx:0x7ffebfb30000
rsi:0x7ffebfb3a330
rdi:0x7ffebfb3a330
rbp:0x0
rsp:0x7ffebfb39770
r8:0x5570a73d6210
r9:0x0
r10:0x5570a73d5010
r11:0x7f2cfe7f0be0
r12:0x5570a6f99080
r13:0x7ffebfb3b800
r14:0x5570a70ccb18
r15:0x0
rip:0x5570a6f9ba3f
eflags:0x202
cs:0x33
ss:0x2b
ds:0x0
es:0x0
fs:0x0
gs:0x0
orig_rax:0xffffffffffffffff
fs_base:0x7f2cfe600880
gs_base:0x0

,return_addresses=[0x1,0x7ffebfb3a330,(nil),(nil),(nil),(nil),(nil),(nil)]}Probable previous-to-duplicated-state at 461:{time:397,ticks:147361,st:7,regs:Printing register file:
rax:0x7ffebfb3a330
rbx:0x7ffebfb3b6e0
rcx:0x7ffebfb3a330
rdx:0x7ffebfb30000
rsi:0x7ffebfb3a330
rdi:0x7ffebfb3a330
rbp:0x0
rsp:0x7ffebfb39670
r8:0x5570a73d6210
r9:0x0
r10:0x5570a73d5010
r11:0x7f2cfe7f0be0
r12:0x5570a6f99080
r13:0x7ffebfb3b800
r14:0x5570a70ccb18
r15:0x0
rip:0x5570a6f9ba3f
eflags:0x202
cs:0x33
ss:0x2b
ds:0x0
es:0x0
fs:0x0
gs:0x0
orig_rax:0xffffffffffffffff
fs_base:0x7f2cfe600880
gs_base:0x0

,return_addresses=[0x20,0x7ffebfb3a330,(nil),(nil),(nil),(nil),(nil),(nil)]}Probable duplicated state at 314:{time:397,ticks:147361,st:7,regs:Printing register file:
rax:0x7ffebfb3a330
rbx:0x7ffebfb3b6e0
rcx:0x7ffebfb3a330
rdx:0x7ffebfb30000
rsi:0x7ffebfb3a330
rdi:0x7ffebfb3a330
rbp:0x0
rsp:0x7ffebfb39770
r8:0x5570a73d6210
r9:0x0
r10:0x5570a73d5010
r11:0x7f2cfe7f0be0
r12:0x5570a6f99080
r13:0x7ffebfb3b800
r14:0x5570a70ccb18
r15:0x0
rip:0x5570a6f9ba43
eflags:0x202
cs:0x33
ss:0x2b
ds:0x0
es:0x0
fs:0x0
gs:0x0
orig_rax:0xffffffffffffffff
fs_base:0x7f2cfe600880
gs_base:0x0

,return_addresses=[0x7ffebfb3a330,0x7ffebfb3a330,(nil),(nil),(nil),(nil),(nil),(nil)]}[FATAL /build/rr-S0CLEN/rr-5.3.0/src/ReplayTimeline.cc:246:mark_after_singlestep() errno: EIO] 
 (task 347368 (rec:347318) at time 397)
 -> Assertion `false' failed to hold.  Probable duplicated states leading to {time:397,ticks:147361,st:7,regs_ip:0x5570a6f9ba43} at index 462
Tail of trace dump:
{
  real_time:220191.444248 global_time:377, event:`SYSCALL: sigaltstack' (state:EXITING_SYSCALL) tid:347320, ticks:24
rax:0x0 rbx:0x83 rcx:0xffffffffffffffff rdx:0x2118710e25b8b069 rsi:0x7f2cfe0fdd00 rdi:0x0 rbp:0x7f2cfdefdfa0 rsp:0x7f2cfdefde10 r8:0x7f2cfe0fe700 r9:0x7f2cfe0fe700 r10:0x7f2cfe0fe9d0 r11:0x246 r12:0x7f2cfdefdef0 r13:0x54cb8 r14:0x3 r15:0x5570a73d5e20 rip:0x70000002 eflags:0x246 cs:0x33 ss:0x2b ds:0x0 es:0x0 fs:0x0 gs:0x0 orig_rax:0x83 fs_base:0x7f2cfe0fe700 gs_base:0x0
  { tid:347320, addr:0x7f2cfe0fdd00, length:0x18 }
}
{
  real_time:220191.444291 global_time:378, event:`SYSCALL: mmap' (state:ENTERING_SYSCALL) tid:347320, ticks:47
rax:0xffffffffffffffda rbx:0x9 rcx:0xffffffffffffffff rdx:0x3 rsi:0x3000 rdi:0x0 rbp:0x7f2cfdefdfa0 rsp:0x7f2cfdefde10 r8:0xffffffff r9:0x0 r10:0x20022 r11:0x246 r12:0x7ffebfb39b3e r13:0x7ffebfb39b3f r14:0x7ffebfb39c00 r15:0x5570a73d5e20 rip:0x70000002 eflags:0x246 cs:0x33 ss:0x2b ds:0x0 es:0x0 fs:0x0 gs:0x0 orig_rax:0x9 fs_base:0x7f2cfe0fe700 gs_base:0x0
}
{
  real_time:220191.444329 global_time:379, event:`SYSCALL: mmap' (state:EXITING_SYSCALL) tid:347320, ticks:47
rax:0x7f2cfe99a000 rbx:0x9 rcx:0xffffffffffffffff rdx:0x3 rsi:0x3000 rdi:0x0 rbp:0x7f2cfdefdfa0 rsp:0x7f2cfdefde10 r8:0xffffffff r9:0x0 r10:0x20022 r11:0x246 r12:0x7ffebfb39b3e r13:0x7ffebfb39b3f r14:0x7ffebfb39c00 r15:0x5570a73d5e20 rip:0x70000002 eflags:0x246 cs:0x33 ss:0x2b ds:0x0 es:0x0 fs:0x0 gs:0x0 orig_rax:0x9 fs_base:0x7f2cfe0fe700 gs_base:0x0
  { map_file:"<ZERO>", addr:0x7f2cfe99a000, length:0x3000, prot_flags:"rw-p", file_offset:0x0, device:0, inode:0, data_file:"", data_offset:0x0, file_size:0x3000 }
}
{
  real_time:220191.444382 global_time:380, event:`SYSCALLBUF_FLUSH' tid:347320, ticks:98
  { syscall:'mprotect', ret:0x0, size:0x10 }
}
{
  real_time:220191.444386 global_time:381, event:`SYSCALL: sigaltstack' (state:ENTERING_SYSCALL) tid:347320, ticks:98
rax:0xffffffffffffffda rbx:0x83 rcx:0xffffffffffffffff rdx:0x7f2cfe7b87f4 rsi:0x0 rdi:0x7f2cfe0fdd00 rbp:0x7f2cfdefdfa0 rsp:0x7f2cfdefde10 r8:0xffffffff r9:0x0 r10:0x20022 r11:0x246 r12:0x7ffebfb39b3e r13:0x7ffebfb39b3f r14:0x7ffebfb39c00 r15:0x5570a73d5e20 rip:0x70000002 eflags:0x246 cs:0x33 ss:0x2b ds:0x0 es:0x0 fs:0x0 gs:0x0 orig_rax:0x83 fs_base:0x7f2cfe0fe700 gs_base:0x0
}
{
  real_time:220191.444388 global_time:382, event:`SYSCALLBUF_RESET' tid:347320, ticks:98
}
{
  real_time:220191.444417 global_time:383, event:`SYSCALL: sigaltstack' (state:EXITING_SYSCALL) tid:347320, ticks:98
rax:0x0 rbx:0x83 rcx:0xffffffffffffffff rdx:0x7f2cfe7b87f4 rsi:0x0 rdi:0x7f2cfe0fdd00 rbp:0x7f2cfdefdfa0 rsp:0x7f2cfdefde10 r8:0xffffffff r9:0x0 r10:0x20022 r11:0x246 r12:0x7ffebfb39b3e r13:0x7ffebfb39b3f r14:0x7ffebfb39c00 r15:0x5570a73d5e20 rip:0x70000002 eflags:0x246 cs:0x33 ss:0x2b ds:0x0 es:0x0 fs:0x0 gs:0x0 orig_rax:0x83 fs_base:0x7f2cfe0fe700 gs_base:0x0
}
{
  real_time:220191.444460 global_time:384, event:`SYSCALL: prctl' (state:ENTERING_SYSCALL) tid:347320, ticks:110
rax:0xffffffffffffffda rbx:0x9d rcx:0xffffffffffffffff rdx:0x0 rsi:0x5570a73d5b40 rdi:0xf rbp:0x7f2cfdefdfa0 rsp:0x7f2cfdefde10 r8:0x0 r9:0x0 r10:0x0 r11:0x246 r12:0x5570a73d5df0 r13:0x7ffebfb39b3f r14:0x7f2cfe99b000 r15:0x5570a73d5e20 rip:0x70000002 eflags:0x246 cs:0x33 ss:0x2b ds:0x0 es:0x0 fs:0x0 gs:0x0 orig_rax:0x9d fs_base:0x7f2cfe0fe700 gs_base:0x0
}
{
  real_time:220191.444494 global_time:385, event:`SYSCALL: prctl' (state:EXITING_SYSCALL) tid:347320, ticks:110
rax:0x0 rbx:0x9d rcx:0xffffffffffffffff rdx:0x0 rsi:0x5570a73d5b40 rdi:0xf rbp:0x7f2cfdefdfa0 rsp:0x7f2cfdefde10 r8:0x0 r9:0x0 r10:0x0 r11:0x246 r12:0x5570a73d5df0 r13:0x7ffebfb39b3f r14:0x7f2cfe99b000 r15:0x5570a73d5e20 rip:0x70000002 eflags:0x246 cs:0x33 ss:0x2b ds:0x0 es:0x0 fs:0x0 gs:0x0 orig_rax:0x9d fs_base:0x7f2cfe0fe700 gs_base:0x0
}
{
  real_time:220191.444537 global_time:386, event:`SYSCALL: mmap' (state:ENTERING_SYSCALL) tid:347320, ticks:149
rax:0xffffffffffffffda rbx:0x9 rcx:0xffffffffffffffff rdx:0x0 rsi:0x8000000 rdi:0x0 rbp:0x7f2cfdefdfa0 rsp:0x7f2cfdefde10 r8:0xffffffff r9:0x0 r10:0x4022 r11:0x246 r12:0xfffffffffffffe70 r13:0x0 r14:0x20 r15:0x0 rip:0x70000002 eflags:0x246 cs:0x33 ss:0x2b ds:0x0 es:0x0 fs:0x0 gs:0x0 orig_rax:0x9 fs_base:0x7f2cfe0fe700 gs_base:0x0
}
{
  real_time:220191.444575 global_time:387, event:`SYSCALL: mmap' (state:EXITING_SYSCALL) tid:347320, ticks:149
rax:0x7f2cf0000000 rbx:0x9 rcx:0xffffffffffffffff rdx:0x0 rsi:0x8000000 rdi:0x0 rbp:0x7f2cfdefdfa0 rsp:0x7f2cfdefde10 r8:0xffffffff r9:0x0 r10:0x4022 r11:0x246 r12:0xfffffffffffffe70 r13:0x0 r14:0x20 r15:0x0 rip:0x70000002 eflags:0x246 cs:0x33 ss:0x2b ds:0x0 es:0x0 fs:0x0 gs:0x0 orig_rax:0x9 fs_base:0x7f2cfe0fe700 gs_base:0x0
  { map_file:"<ZERO>", addr:0x7f2cf0000000, length:0x8000000, prot_flags:"---p", file_offset:0x0, device:0, inode:0, data_file:"", data_offset:0x0, file_size:0x8000000 }
}
{
  real_time:220191.444616 global_time:388, event:`SYSCALL: munmap' (state:ENTERING_SYSCALL) tid:347320, ticks:161
rax:0xffffffffffffffda rbx:0xb rcx:0xffffffffffffffff rdx:0x0 rsi:0x4000000 rdi:0x7f2cf4000000 rbp:0x7f2cfdefdfa0 rsp:0x7f2cfdefde10 r8:0xffffffff r9:0x0 r10:0x4022 r11:0x246 r12:0x7f2cf0000000 r13:0x0 r14:0x20 r15:0x0 rip:0x70000002 eflags:0x246 cs:0x33 ss:0x2b ds:0x0 es:0x0 fs:0x0 gs:0x0 orig_rax:0xb fs_base:0x7f2cfe0fe700 gs_base:0x0
}
{
  real_time:220191.444654 global_time:389, event:`SYSCALL: munmap' (state:EXITING_SYSCALL) tid:347320, ticks:161
rax:0x0 rbx:0xb rcx:0xffffffffffffffff rdx:0x0 rsi:0x4000000 rdi:0x7f2cf4000000 rbp:0x7f2cfdefdfa0 rsp:0x7f2cfdefde10 r8:0xffffffff r9:0x0 r10:0x4022 r11:0x246 r12:0x7f2cf0000000 r13:0x0 r14:0x20 r15:0x0 rip:0x70000002 eflags:0x246 cs:0x33 ss:0x2b ds:0x0 es:0x0 fs:0x0 gs:0x0 orig_rax:0xb fs_base:0x7f2cfe0fe700 gs_base:0x0
}
{
  real_time:220191.444711 global_time:390, event:`SYSCALLBUF_FLUSH' tid:347320, ticks:385
  { syscall:'mprotect', ret:0x0, size:0x10 }
}
{
  real_time:220191.444715 global_time:391, event:`SYSCALL: sched_getaffinity' (state:ENTERING_SYSCALL) tid:347320, ticks:385
rax:0xffffffffffffffda rbx:0x7f2cfe0fe700 rcx:0xffffffffffffffff rdx:0x7f2cf0000b60 rsi:0x20 rdi:0x54cb8 rbp:0x7f2cfe0fdc00 rsp:0x7f2cfe0fdb28 r8:0x20 r9:0x0 r10:0x4022 r11:0x246 r12:0x7f2cfe0fed18 r13:0x7f2cf0000b60 r14:0x20 r15:0x0 rip:0x7f2cfe961684 eflags:0x246 cs:0x33 ss:0x2b ds:0x0 es:0x0 fs:0x0 gs:0x0 orig_rax:0xcc fs_base:0x7f2cfe0fe700 gs_base:0x0
}
{
  real_time:220191.444717 global_time:392, event:`SYSCALLBUF_RESET' tid:347320, ticks:385
}
{
  real_time:220191.444753 global_time:393, event:`SYSCALL: sched_getaffinity' (state:EXITING_SYSCALL) tid:347320, ticks:385
rax:0x8 rbx:0x7f2cfe0fe700 rcx:0xffffffffffffffff rdx:0x7f2cf0000b60 rsi:0x20 rdi:0x54cb8 rbp:0x7f2cfe0fdc00 rsp:0x7f2cfe0fdb28 r8:0x20 r9:0x0 r10:0x4022 r11:0x246 r12:0x7f2cfe0fed18 r13:0x7f2cf0000b60 r14:0x20 r15:0x0 rip:0x7f2cfe961684 eflags:0x246 cs:0x33 ss:0x2b ds:0x0 es:0x0 fs:0x0 gs:0x0 orig_rax:0xcc fs_base:0x7f2cfe0fe700 gs_base:0x0
  { tid:347320, addr:0x7f2cf0000b60, length:0x8 }
}
{
  real_time:220191.444799 global_time:394, event:`SYSCALL: futex' (state:ENTERING_SYSCALL) tid:347320, ticks:531
rax:0xffffffffffffffda rbx:0xca rcx:0xffffffffffffffff rdx:0xffffffff rsi:0x80 rdi:0x5570a73d5dd8 rbp:0x7f2cfdefdfa0 rsp:0x7f2cfdefde10 r8:0x0 r9:0x5570a705e650 r10:0x0 r11:0x246 r12:0x7f2cfe720880 r13:0x7ffebfb39b3f r14:0x5570a73d5db0 r15:0x0 rip:0x70000002 eflags:0x246 cs:0x33 ss:0x2b ds:0x0 es:0x0 fs:0x0 gs:0x0 orig_rax:0xca fs_base:0x7f2cfe0fe700 gs_base:0x0
}
{
  real_time:220191.444815 global_time:395, event:`SYSCALL: clone' (state:EXITING_SYSCALL) tid:347318, ticks:144530
rax:0x54cb8 rbx:0x7f2cfe0fe700 rcx:0xffffffffffffffff rdx:0x7f2cfe0fe9d0 rsi:0x7f2cfe0fde70 rdi:0x3d0f00 rbp:0x7ffebfb39c00 rsp:0x7ffebfb39a88 r8:0x7f2cfe0fe700 r9:0x7f2cfe0fe700 r10:0x7f2cfe0fe9d0 r11:0x246 r12:0x7ffebfb39b3e r13:0x7ffebfb39b3f r14:0x7ffebfb39c00 r15:0x7f2cfe0fde80 rip:0x7f2cfe727285 eflags:0x246 cs:0x33 ss:0x2b ds:0x0 es:0x0 fs:0x0 gs:0x0 orig_rax:0x38 fs_base:0x7f2cfe600880 gs_base:0x0
}
{
  real_time:220191.444922 global_time:396, event:`SYSCALLBUF_FLUSH' tid:347318, ticks:147418
  { syscall:'futex', ret:0x1, size:0x14 }
}
{
  real_time:220191.444966 global_time:397, event:`PATCH_SYSCALL' tid:347318, ticks:147418
rax:0x1 rbx:0x5570a70d06 rcx:0xffffffffffffffff rdx:0x2 rsi:0x5570a7084093 rdi:0x1 rbp:0x2 rsp:0x7ffebfb391c0 r8:0x0 r9:0x0 r10:0x5570a73d5010 r11:0x246 r12:0x7ffebfb39340 r13:0x5570a70d94c8 r14:0x2 r15:0x5570a7084093 rip:0x7f2cfe9602cd eflags:0x246 cs:0x33 ss:0x2b ds:0x0 es:0x0 fs:0x0 gs:0x0 orig_rax:0xffffffffffffffff fs_base:0x7f2cfe600880 gs_base:0x0
  { tid:347318, addr:0x7f2cfe98b6ca, length:0x4f }
  { tid:347318, addr:0x7f2cfe9602cd, length:0x5 }
  { tid:347318, addr:0x7f2cfe9602d2, length:0x3 }
}
{
  real_time:220191.444969 global_time:398, event:`SYSCALLBUF_RESET' tid:347318, ticks:147418
}
=== Start rr backtrace:
rr(_ZN2rr13dump_rr_stackEv+0x5a)[0x5648ab7c165a]
rr(_ZN2rr9GdbServer15emergency_debugEPNS_4TaskE+0x635)[0x5648ab6d8795]
rr(+0xb33e1)[0x5648ab6e93e1]
rr(_ZN2rr21EmergencyDebugOstreamD2Ev+0x75)[0x5648ab6e95b5]
rr(_ZN2rr14ReplayTimeline21mark_after_singlestepERKNS0_4MarkERKNS_12ReplayResultE+0x310)[0x5648ab77af30]
rr(_ZN2rr14ReplayTimeline18reverse_singlestepERKNS0_4MarkERKNS_10TaskishUidINS_4TaskEEElRKSt8functionIFbPNS_10ReplayTaskEEERKS9_IFbvEE+0x1f9a)[0x5648ab78053a]
rr(_ZN2rr14ReplayTimeline18reverse_singlestepERKNS_10TaskishUidINS_4TaskEEElRKSt8functionIFbPNS_10ReplayTaskEEERKS6_IFbvEE+0x66)[0x5648ab783056]
rr(_ZN2rr9GdbServer14debug_one_stepERNS_10GdbRequestE+0xd4c)[0x5648ab6daeec]
rr(_ZN2rr9GdbServer12serve_replayERKNS0_15ConnectionFlagsE+0x6fb)[0x5648ab6dc17b]
rr(+0x124dff)[0x5648ab75adff]
rr(_ZN2rr13ReplayCommand3runERSt6vectorINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESaIS7_EE+0x4ca)[0x5648ab75be1a]
rr(main+0x282)[0x5648ab68c8a2]
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf3)[0x7ff4537b50b3]
rr(_start+0x2e)[0x5648ab68c9ee]
=== End rr backtrace
Launch gdb with
  gdb '-l' '10000' '-ex' 'set sysroot /' '-ex' 'target extended-remote 127.0.0.1:19688' /home/al/.local/share/rr/async_rs-2/mmap_hardlink_3_async_rs

rr --version # rr version 5.3.0

Reproduce the issue using the provided src/main.rs and Cargo dependencies: run cargo build, rr record target/debug/async_rs, then rr replay. Start at the GDB breakpoint on async_rs:🅱️:{{closure}} and test reverse-next across a().await. Done means reverse stepping no longer triggers the duplicated-state assertion and fatal ReplayTimeline error.