Hi,

With the latest upload (2022-09-16 14:41) I wanted to compare some older projects that I've used with MKIV to the LMTX 2.10.00.

In one of which I am using the Lato 2.0 font (https://packages.debian.org/sid/fonts-lato).
With MKIV I get the correct output but LMTX complains about not being able to find the font.

There seems to be an issue with the typescript file type-imp-lato.mkiv.

MWE:
\setupbodyfont[lato,12pt]
\starttext
Hello World!
\stoptext

---
ConTeXt  ver: 2022.09.11 20:44 MKIV - luatex version: 1.1501, functionality level: 7539:

mtxrun --script fonts --list --all --pattern=*lato*
identifier           familyname   fontname             filename                  subfont   instances

latoblack            lato         latoblack            Lato-Bla.ttf
latoblackitalic      lato         latoblackitalic      Lato-BlackItalic.ttf
latobold             lato         latobold             Lato-Bol.ttf
latobolditalic       lato         latobolditalic       Lato-BoldItalic.ttf
latoextrabold        lato         latoheavy            Lato-Heavy.ttf
latoextralight       lato         latothin             Lato-Thin.ttf
latohairline         lato         latohairline         Lato-Hai.ttf
latohairlineitalic   lato         latohairlineitalic   Lato-HaiIta.ttf
latoheavy            lato         latoheavy            Lato-Heavy.ttf
latoheavyitalic      lato         latoheavyitalic      Lato-HeavyItalic.ttf
latoitalic           lato         latoitalic           Lato-Italic.ttf
latolight            lato         latolight            Lato-Lig.ttf
latolightitalic      lato         latolightitalic      Lato-LightItalic.ttf
latomedium           lato         latomedium           Lato-Medium.ttf
latomediumitalic     lato         latomediumitalic     Lato-MediumItalic.ttf
latonormal           lato         latohairline         Lato-Hai.ttf
latoregular          lato         latoregular          Lato-Reg.ttf
latosemibold         lato         latosemibold         Lato-Semibold.ttf
latosemibolditalic   lato         latosemibolditalic   Lato-SemiboldItalic.ttf
latothin             lato         latothin             Lato-Thin.ttf
latothinitalic       lato         latothinitalic       Lato-ThinItalic.ttf

fonts           > otf loading > loading '/usr/share/texlive/texmf-dist/fonts/truetype/typoland/lato/Lato-Regular.ttf', hash 'lato-regular'

mkiv lua stats  > loaded fonts: 3 files: xitsmath-bold.otf, xitsmath-regular.otf, lato-regular.ttf
---
ConTeXt  ver: 2022.09.11 20:44 LMTX - luametatex version: 2.1, functionality level: 20220918:

mtxrun --script fonts --list --all --pattern=*lato*
identifier           familyname   fontname             filename                  subfont   instances

latoblack            lato         latoblack            Lato-Bla.ttf
latoblackitalic      lato         latoblackitalic      Lato-BlackItalic.ttf
latobold             lato         latobold             Lato-Bol.ttf
latobolditalic       lato         latobolditalic       Lato-BoldItalic.ttf
latoextrabold        lato         latoheavy            Lato-Heavy.ttf
latoextralight       lato         latothin             Lato-Thin.ttf
latohairline         lato         latohairline         Lato-Hai.ttf
latohairlineitalic   lato         latohairlineitalic   Lato-HaiIta.ttf
latoheavy            lato         latoheavy            Lato-Heavy.ttf
latoheavyitalic      lato         latoheavyitalic      Lato-HeavyItalic.ttf
latoitalic           lato         latoitalic           Lato-Italic.ttf
latolight            lato         latolight            Lato-Lig.ttf
latolightitalic      lato         latolightitalic      Lato-LightItalic.ttf
latomedium           lato         latomedium           Lato-Medium.ttf
latomediumitalic     lato         latomediumitalic     Lato-MediumItalic.ttf
latonormal           lato         latohairline         Lato-Hai.ttf
latoregular          lato         latoregular          Lato-Reg.ttf
latosemibold         lato         latosemibold         Lato-Semibold.ttf
latosemibolditalic   lato         latosemibolditalic   Lato-SemiboldItalic.ttf
latothin             lato         latothin             Lato-Thin.ttf
latothinitalic       lato         latothinitalic       Lato-ThinItalic.ttf

close source    > level 2, order 6, name '/usr/share/texmf/tex/context/fonts/mkiv/type-imp-lato.mkiv'
fonts           > defining > font with asked name 'lato-regular' is not found using lookup 'file'
fonts           > defining > unable to define 'lato-regular' as 'lato-12pt-ss-tf-0--0'
---

If I change the file: reference I get it working with both MKIV/LMTX:

    \starttypescript [\s!sans] [lato] [\s!name]
        \setups[\s!font:\s!fallback:\s!sans]
        % \definefontsynonym [\s!Sans]           [\s!file:lato-regular]    [\s!features=\s!default]
        % \definefontsynonym [\s!SansBold]       [\s!file:lato-bold]       [\s!features=\s!default]
        \definefontsynonym [\s!Sans]           [\s!file:lato-reg]    [\s!features=\s!default]
        \definefontsynonym [\s!SansBold]       [\s!file:lato-bol]       [\s!features=\s!default]
        \definefontsynonym [\s!SansItalic]     [\s!file:lato-italic]     [\s!features=\s!default]
        \definefontsynonym [\s!SansBoldItalic] [\s!file:lato-bolditalic] [\s!features=\s!default]
    \stoptypescript

mkiv lua stats  > loaded fonts: 3 files: xitsmath-bold.otf, xitsmath-regular.otf, lato-reg.ttf

Does MKIV handle fonts differently to LMTX? I can see some tma/tmc references in MKIV:
system          > lua > compiling '/home/reviczky/.texlive2021/texmf-var/luatex-cache/context/e570cb3e0e3ab0118ca08dd148bbec7d/fonts/otl/lato-regular.tma' into '/home/reviczky/.texlive2021/texmf-var/luatex-cache/context/e570cb3e0e3ab0118ca08dd148bbec7d/fonts/otl/lato-regular.tmc'
system          > lua > dumping '/home/reviczky/.texlive2021/texmf-var/luatex-cache/context/e570cb3e0e3ab0118ca08dd148bbec7d/fonts/otl/lato-regular.tma' into '/home/reviczky/.texlive2021/texmf-var/luatex-cache/context/e570cb3e0e3ab0118ca08dd148bbec7d/fonts/otl/lato-regular.tmc' stripped

But looking at the mtxrun font list I cannot see the "lato-regular", so not sure how MKIV points to /usr/share/texlive/texmf-dist/fonts/truetype/typoland/lato/Lato-Regular.ttf.

I am cleaning the cache and do a generate and fonts reload each time.

Is changing the type-imp-lato.mkiv as above the right approach to get lato working in both MKIV and LMTX?

Thanks,
Adam