#1519 Congestion issue Issue created by jaquerinte Description I'm trying to synthesize a previous MPW-2 design in the new Openlane for the gf180 PDK but always gets to: "Reached 20 congestion iterations with less than 15% of reduction between iterations. Routing congestion too high. Check the congestion heatmap in the GUI." And I try to use as much space as possible and the lowest possible PL_TARGET_DENSITY but always gets to that message. Expected Behavior Openlane finish execution Environment report

Kernel: Linux v5.15.0-53-generic
Distribution: ubuntu 22.04
Python: v3.10.6 (OK)
Container Engine: docker v20.10.20 (OK)
OpenLane Git Version: cb59d1f84deb5cedbb5b0a3e3f3b4129a967c988
pip: INSTALLED
python-venv: INSTALLED
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PDK Version Verification Status: FAILED
/home/storage/programs/chip_making/space_shuttle_gf_node/dependencies/openlane_src/pdks/sky130A not found.
Traceback (most recent call last):
  File "/home/storage/programs/chip_making/space_shuttle_gf_node/dependencies/openlane_src/dependencies/verify_versions.py", line 72, in verify_versions
    raise Exception(f"{pdk_dir} not found.")
Exception: /home/storage/programs/chip_making/space_shuttle_gf_node/dependencies/openlane_src/pdks/sky130A not found.

Failed to verify sky130A.
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Git Log (Last 3 Commits)

cb59d1f 2022-11-18T18:42:38+02:00 fix return values in `equally_spaced_sequence` (#1503) - Kareem Farid -  (grafted, HEAD, tag: 2022.11.19)
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Git Remotes

origin  <https://github.com/The-OpenROAD-Project/OpenLane> (fetch)
origin  <https://github.com/The-OpenROAD-Project/OpenLane> (push)

Reproduction material issue.tar.gz Relevant log output

[INFO GRT-0101] Running extra iterations to remove overflow.
[WARNING GRT-0227] Reached 20 congestion iterations with less than 15% of reduction between iterations.
[INFO GRT-0197] Via related to pin nodes: 392828
[INFO GRT-0198] Via related Steiner nodes: 33050
[INFO GRT-0199] Via filling finished.
[INFO GRT-0111] Final number of vias: 652988
[INFO GRT-0112] Final usage 3D: 4188682
[ERROR GRT-0118] Routing congestion too high. Check the congestion heatmap in the GUI.
Error: resizer_routing_timing.tcl, 39 GRT-0118
child process exited abnormally

[ERROR]: Creating issue reproducible...
[ERROR]: Flow failed.

Launched Code make user_proj_example Project git https://github.com/jaquerinte/space_shuttle_gf_node The-OpenROAD-Project/OpenLane