The bug
The warning message "Command block chain tried to execute more than x steps!" appears in the log even when no or less command blocks should run.
It looks like the message appears if there could be chain command block behind and additionally seems to count impulse and repeating command blocks as well.
Note: Spelling fixes described in MC-118258 are applied.
Commandblock chain tried to execure
How to reproduce
Set the gamerule
maxCommandChainLength
to 1/gamerule maxCommandChainLength 1
Place an impulse command block and power it
Look at the log
→ The warning message appeared, despite the fact that it should not have appeared
→ Also note that only one command block run and therefore no warning message should appear at all
Can confirm for MC 1.12.1.