I'm not sure if this is the correct place to report a bug. If not, please tell me where to post it.
Compiler: GNU GCC 5.4.0
Compiled on: Jun 24 2018
Qt Version: 5.5.1
Boost Version: 1.58.0
System: Linux Mint 18.3
As the screenshot shows, when drawing a two point line using the polar coordinate something is wrong. I selected the start point of the line in the upper right hand and then entered 2<45. The LibreCAD then drew the line down and to the left and made it much longer that two units.
Selecting the Angle tool and entering the values in the boxes works as expected.
When you enter 2<45 this is an absolute position!
Measure the endpoint of the line and you will see that it is at X1.4142,Y1.4142, which is 2<45 from origin (0,0).
If you want a line of 2 units and 45° from the first click of the line command, you have to enter @2<45 for a relative position.
The @ makes the difference.