The key is double clicking when at the second point of the line (otherwise, nothing will be drawn).
Do:
- Select the Bezier drawing tool. In later versions of Inkscape there is also a help text for this tool that indicates that it can be used to draw straight lines.
- Left click for the first point of the line.
- Drag to the position of the second point of the line.
- Double click.

IMHO, "drag" isn't the right word. Dragging means clicking and holding. In order to draw a straight line, you don't need to hold. Just move the mouse.
ReplyDeleteThe procedure has multiple alternatives as well.
1. Select the tool
2. Click at the start of the line
3. Double click at the end of the line
Or:
1. Select the tool
2. Click at the start of the line
3. Click at the end of the line
4. Right click to end the line
Or:
1. Select the tool
2. Click at the start of the line
3. Click at the end of the line
4. Press Enter to end the line