IR Drop heatmap complains about not being populated with data and then shows a heat map

[jeffng-or]

Subject

[Stage]: Other. Please describe below.

Describe the bug

After running analyze_power_grid on both VDD and VSS, I pulled up the IR Drop heatmap and it complains:

[INFO PSM-0040] All shapes on net VDD are connected.
########## IR report #################
Net              : VDD
Corner           : default
Total power      : 7.55e-04 W
Supply voltage   : 7.70e-01 V
Worstcase voltage: 7.66e-01 V
Average voltage  : 7.68e-01 V
Average IR drop  : 1.63e-03 V
Worstcase IR drop: 3.86e-03 V
Percentage drop  : 0.50 %
######################################
[INFO PSM-0040] All shapes on net VSS are connected.
########## IR report #################
Net              : VSS
Corner           : default
Total power      : 7.55e-04 W
Supply voltage   : 0.00e+00 V
Worstcase voltage: 3.76e-03 V
Average voltage  : 1.70e-03 V
Average IR drop  : 1.70e-03 V
Worstcase IR drop: 3.76e-03 V
Percentage drop  : 0.49 %
######################################
[WARNING GUI-0066] Heat map "IR Drop" has not been populated with data.

and then displays what looks like a valid IR Drop heatmap.

What data is missing?

Expected Behavior

If there's no data, then a heatmap shouldn't be displayed, right?

If there's data, then why warn?

Environment

orfs git commit tag: ceb386103ac58f0f6fe250e7de65897c4cb865f6

To Reproduce

mkissue tarball: https://drive.google.com/file/d/1of18W5aayLPTp6QjetSJF7DmfgojbjNJ/view?usp=drive_link

Relevant log output

Screenshots

No response

Additional Context

No response