Crash During Clock Tree Synthesis

[donn]

• Tested on: OpenROAD v2.0-4149-gf2466c46e (f2466c4)

Appears that there's a crash during CTS on a particularly complex design.

[INFO CTS-0036]  Average source sink dist: 11043.00 dbu.
[INFO CTS-0037]  Number of outlier sinks: 0.
[INFO CTS-0018]     Created 17 clock buffers.
[INFO CTS-0012]     Minimum number of buffers in the clock path: 5.
[INFO CTS-0013]     Maximum number of buffers in the clock path: 5.
[INFO CTS-0015]     Created 17 clock nets.
[INFO CTS-0016]     Fanout distribution for the current clock = 9:1, 10:1, 13:2, 14:2, 18:1, 20:1..
[INFO CTS-0017]     Max level of the clock tree: 3.
[INFO CTS-0018]     Created 7 clock buffers.
[INFO CTS-0012]     Minimum number of buffers in the clock path: 3.
[INFO CTS-0013]     Maximum number of buffers in the clock path: 3.
[INFO CTS-0015]     Created 7 clock nets.
[INFO CTS-0016]     Fanout distribution for the current clock = 8:1, 11:1, 12:1, 18:1..
[INFO CTS-0017]     Max level of the clock tree: 2.
[INFO CTS-0018]     Created 76 clock buffers.
[INFO CTS-0012]     Minimum number of buffers in the clock path: 5.
[INFO CTS-0013]     Maximum number of buffers in the clock path: 7.
[INFO CTS-0015]     Created 76 clock nets.
[INFO CTS-0016]     Fanout distribution for the current clock = 2:3, 3:3, 4:2, 5:4, 6:4, 7:7, 8:5, 9:5, 10:2, 11:4, 12:4, 13:5, 14:4, 15:2, 16:3, 17:2, 18:3, 20:3, 23:1..
[INFO CTS-0017]     Max level of the clock tree: 3.
[INFO CTS-0018]     Created 3 clock buffers.
[INFO CTS-0012]     Minimum number of buffers in the clock path: 2.
[INFO CTS-0013]     Maximum number of buffers in the clock path: 2.
[INFO CTS-0015]     Created 3 clock nets.
[INFO CTS-0016]     Fanout distribution for the current clock = 2:1, 3:1..
[INFO CTS-0017]     Max level of the clock tree: 1.
[INFO CTS-0018]     Created 3 clock buffers.
[INFO CTS-0012]     Minimum number of buffers in the clock path: 2.
[INFO CTS-0013]     Maximum number of buffers in the clock path: 2.
[INFO CTS-0015]     Created 3 clock nets.
[INFO CTS-0016]     Fanout distribution for the current clock = 1:2..
[INFO CTS-0017]     Max level of the clock tree: 1.
Stack trace:
 0# 0x000055B35B75EEF5 in openroad
 1# 0x00007F5DDA63E8E0 in /usr/lib/libc.so.6
 2# odb::dbInst::setSourceType(odb::dbSourceType) in openroad
 3# 0x000055B35C03A6A5 in openroad
 4# cts::Clock::forEachClockBuffer(std::function<void (cts::ClockInst&)> const&) in openroad
 5# cts::TritonCTS::createClockBuffers(cts::Clock&) in openroad
 6# cts::TritonCTS::writeClockNetsToDb(cts::Clock&) in openroad
 7# cts::TritonCTS::writeDataToDb() in openroad
 8# 0x000055B35C055E45 in openroad
 9# TclNRRunCallbacks in /usr/lib/libtcl.so
10# 0x00007F5DDC805BDB in /usr/lib/libtcl.so
11# Tcl_EvalEx in /usr/lib/libtcl.so
12# Tcl_Eval in /usr/lib/libtcl.so
13# sta::sourceTclFile(char const*, bool, bool, Tcl_Interp*) in openroad
14# ord::tclAppInit(Tcl_Interp*) in openroad
15# Tcl_MainEx in /usr/lib/libtcl.so
16# main in openroad
17# 0x00007F5DDA629290 in /usr/lib/libc.so.6
18# __libc_start_main in /usr/lib/libc.so.6
19# _start in openroad

reproducible.tar.gz

[maliberty]

What is the purpose of:

create_generated_clock -name csclk_slow -source [get_ports {mgmt_gpio_in[4]}]  -divide_by 1 [get_pins {_5096_/X}]

5096 is an AOI gate not a clock gating cell. Why divide by 1?
(I'll fix the crash but I'm not clear what the expect result is).