Best illustrated in the attached screenshot. There is an error here, and the text shown in the screenshot is the corresponding message. This message occupies one "cell" in the output pane, but this cell can only be shown from the top; if you try to scroll down to read the rest (there are many more lines of text) the cell is hidden and skips to the next error message.

The only way to read all of the text is to resize the build issues pane as large as needed and hope it fits.