font problems with the latest master in MacOS helvetia is used and not DejaVi Mono as in emacs28

[Uwe Brauer]

Hi

Finally I solved my problem in MacO10.15 and successfully compiled and
installed the current  master version.

However I am facing now a font problem. My entry in my custom-init file
is 
 '(default ((t (:inherit nil :stipple nil :background "grey98"
 :foreground "black" :inverse-video nil :box nil :strike-through nil
 :overline nil :underline nil :slant normal :weight normal :height 160
 :width normal :foundry "PfEd" :family "DejaVu Sans Mono"))))

Now indeed in emacs28 C-u C-x = gives 
,----
|              position: 2303 of 64364 (4%), column: 23
|             character: C-j (displayed as C-j) (codepoint 10, #o12, #xa)
|               charset: ascii (ASCII (ISO646 IRV))
| code point in charset: 0x0A
|                script: latin
|                syntax: >      which means: endcomment
|              to input: type "C-x 8 RET a" or "C-x 8 RET LINE FEED (LF)"
|           buffer code: #x0A
|             file code: #x0A (encoded by coding system utf-8-unix)
|               display: by this font (glyph code)
|     mac-ct:-*-DejaVu Sans Mono-normal-normal-normal-*-16-*-*-*-m-0-iso10646-1 
(#x03)
| 
| Character code properties: customize what to show
|   old-name: LINE FEED (LF)
|   general-category: Cc (Other, Control)
`----

However when I start emacs29 helvetica is used which is a proportional
font, and looks terrible in most circumstances, especially in dired

Here is what C-u C-x = 
gives

,----
|              position: 54 of 1045 (5%), column: 53
|             character: C-j (displayed as C-j) (codepoint 10, #o12, #xa)
|               charset: ascii (ASCII (ISO646 IRV))
| code point in charset: 0x0A
|                script: latin
|                syntax:        which means: whitespace
|              to input: type "C-x 8 RET a" or "C-x 8 RET LINE FEED (LF)"
|           buffer code: #x0A
|             file code: #x0A (encoded by coding system undecided-unix)
|               display: by this font (glyph code):
|     mac-ct:-*-Helvetica-medium-normal-normal-*-16-*-*-*-p-0-iso10646-1 (#x02)
| 
| Character code properties: customize what to show
|   old-name: LINE FEED (LF)
|   general-category: Cc (Other, Control)
| 
| 
`----

Who is the culprit here?
What shall I do?

Thanks

Uwe Brauer