Generating of DFFRAM macro fails during Power Delivery Network generation

[boehmerst]

Hi,
The generation of the DFFRAM macro fails during pdn generation. I know that rebuilding any macros from the non user area is not required. However, as I like to generate a similar macro for my user space area I started the build flow from within the openlane folder to study the build details. The build flow breaks with the following error log:

[INFO PDN-0016] Power Delivery Network Generator: Generating PDN
config: /project/openlane/DFFRAM/pdn.tcl
Error: pdn.tcl, 30 TypeError in method 'microns_to_dbu', argument 1 of type 'double'
[ERROR]: during executing: "openroad -exit /openlane/scripts/openroad/or_pdn.tcl |& tee >&@stdout /project/openlane/DFFRAM/runs/DFFRAM/logs/floorplan/7-pdn.log"
[ERROR]: Exit code: 1
[ERROR]: Last 10 lines:
child process exited abnormally

With the following call history:

"try_catch $::env(OPENROAD_BIN) -exit $::env(SCRIPTS_DIR)/openroad/or_pdn.tcl |& tee $::env(TERMINAL_OUTPUT) [index_file $::env(pdn_log_file_tag).log ..."
(procedure "gen_pdn" line 8)
invoked from within
"gen_pdn"
(procedure "run_power_grid_generation" line 94)
invoked from within
"run_power_grid_generation"
(procedure "run_floorplan" line 40)
invoked from within
"[lindex $step_exe 0] [lindex $step_exe 1] "
(procedure "run_non_interactive_mode" line 43)
invoked from within
"run_non_interactive_mode {*}$argv"
invoked from within
"if { [info exists flags_map(-interactive)] || [info exists flags_map(-it)] } {
puts_info "Running interactively"
if { [info exists arg_values(-file)..."
(file "/openlane/flow.tcl" line 356)
make: *** [Makefile:43: DFFRAM] Error 1

I used the OpenLane and pdk versions as installed by the caravan Makefiles. Also building other macros results in the same error log. Any help is highly appreciated.

Stephan