Hi Hans,
No, I did not check this file but only update context Standalone. I guess this is not enough since the compilation does not work.
Thank you
Fabrice

Running `ConTeXt Full' on `ntg80' with ``context --purgeall --nonstop ntg80.tex''

resolvers       | trees | analyzing 'home:texmf'
mtx-context     | run 1: luatex --fmt="/home/fab/context/tex/texmf-cache/luatex-cache/context/5fe67e0bfe781ce0dde776fb1556f32e/formats/luatex/cont-en" --interaction="nonstopmode" --jobname="ntg80" --lua="/home/fab/context/tex/texmf-cache/luatex-cache/context/5fe67e0bfe781ce0dde776fb1556f32e/formats/luatex/cont-en.lui" --no-parse-first-line --c:currentrun=1 --c:fulljobname="./ntg80.tex" --c:input="./ntg80.tex" --c:kindofrun=1 --c:maxnofruns=9 --c:nonstopmode --c:purgeall "cont-yes.mkiv"
This is LuaTeX, Version 1.07.0 (TeX Live 2018)
 system commands enabled.

resolvers       > trees > analyzing 'home:texmf'
open source     > level 1, order 1, name '/home/fab/context/tex/texmf-context/tex/context/base/mkiv/cont-yes.mkiv'
system          >
system          > ConTeXt  ver: 2018.03.16 22:20 MKIV beta  fmt: 2018.3.20  int: english/english
system          >
system          > 'cont-new.mkiv' loaded
open source     > level 2, order 2, name '/home/fab/context/tex/texmf-context/tex/context/base/mkiv/cont-new.mkiv'
close source    > level 2, order 2, name '/home/fab/context/tex/texmf-context/tex/context/base/mkiv/cont-new.mkiv'

system          > files > jobname 'ntg80', input './ntg80', result 'ntg80'
fonts           > latin modern fonts are not preloaded
languages       > language 'en' is active
open source     > level 2, order 3, name '/home/fab/ntg80.tex'
metapost        > library 'mat' is loaded
open source     > level 3, order 4, name '/home/fab/context/tex/texmf-context/tex/context/base/mkiv/meta-imp-mat.mkiv'
close source    > level 3, order 4, name '/home/fab/context/tex/texmf-context/tex/context/base/mkiv/meta-imp-mat.mkiv'
fonts           > preloading latin modern fonts (second stage)
fonts           > 'fallback modern-designsize rm 12pt' is loaded
metapost        > initializing instance 'metafun' using format 'metafun'
metapost        > loading 'metafun' as '/home/fab/context/tex/texmf-context/metapost/context/base/mpiv/metafun.mpiv' using method 'default'
metapost        > initializing number mode 'scaled'

tex error       > mp error on line 61 in file /home/fab/ntg80.tex:

>> math_stacker_draw
! Isolated expression.
<to be read again>
(
<*>  math_stacker_draw(
math_stacker_leftarrow_shape) ; ;
I couldn't find an `=' or `:=' after the
expression that is shown above this error message,
so I guess I'll just ignore it and carry on.

! Extra tokens will be flushed.
<to be read again>
(
<*>  math_stacker_draw(
math_stacker_leftarrow_shape) ; ;
I've just read as much of that statement as I could fathom,
so a semicolon should have been next. It's very puzzling...
but I'll try to get myself back together, by ignoring
everything up to the next `;'. Please insert a semicolon
now in front of anything that you don't want me to delete.
(See Chapter 27 of The METAFONTbook for an example.)

[1]

51    
52     $\overbracket   {a+b+c+d} \quad \underbracket    {a+b+c+d} \quad
53     \doublebracket{a+b+c+d}$ \blank
54     $\overparent    {a+b+c+d} \quad \underparent     {a+b+c+d} \quad
55     \doubleparent {a+b+c+d}$ \blank
56     $\overbrace     {a+b+c+d} \quad \underbrace      {a+b+c+d} \quad
57     \doublebrace  {a+b+c+d}$ \blank
58     $\overbar       {a+b+c+d} \quad \underbar        {a+b+c+d} \quad
59     \doublebar    {a+b+c+d}$ \blank
60    
61 >>  $\overleftarrow  {a+b+c+d} \quad \overrightarrow  {a+b+c+d} $ \blank
62     $\underleftarrow {a+b+c+d} \quad \underrightarrow {a+b+c+d} $ \blank
63    
64     \stoptext


metapost        > error: unknown, no error, terminal or log messages

tex error       > mp error on line 3 in file /home/fab/ntg80.tex:

>> math_stacker_draw
! Isolated expression.
<to be read again>
(
<*>  math_stacker_draw(
math_stacker_leftarrow_shape) ; ;
I couldn't find an `=' or `:=' after the
expression that is shown above this error message,
so I guess I'll just ignore it and carry on.

! Extra tokens will be flushed.
<to be read again>
(
<*>  math_stacker_draw(
math_stacker_leftarrow_shape) ; ;
I've just read as much of that statement as I could fathom,
so a semicolon should have been next. It's very puzzling...
but I'll try to get myself back together, by ignoring
everything up to the next `;'. Please insert a semicolon
now in front of anything that you don't want me to delete.
(See Chapter 27 of The METAFONTbook for an example.)

[1]

 1    
 2     \useMPlibrary[mat]
 3 >> 
 4     % will be in meta-imp-mat.mkiv
 5    
 6     \startMPextensions
 7          vardef math_stacker_arrow_shape =
 8              image (
 9                  drawarrow
10                      (OverlayWidth,OverlayOffset) -- (0,OverlayOffset)
11                  withcolor
12                      OverlayLineColor ;
13                  setbounds currentpicture to boundingbox currentpicture


metapost        > error: unknown, no error, terminal or log messages

tex error       > mp error on line 61 in file /home/fab/ntg80.tex:

>> math_stacker_draw
! Isolated expression.
<to be read again>
(
<*>  math_stacker_draw(
math_stacker_rightarrow_shape) ; ;
I couldn't find an `=' or `:=' after the
expression that is shown above this error message,
so I guess I'll just ignore it and carry on.

! Extra tokens will be flushed.
<to be read again>
(
<*>  math_stacker_draw(
math_stacker_rightarrow_shape) ; ;
I've just read as much of that statement as I could fathom,
so a semicolon should have been next. It's very puzzling...
but I'll try to get myself back together, by ignoring
everything up to the next `;'. Please insert a semicolon
now in front of anything that you don't want me to delete.
(See Chapter 27 of The METAFONTbook for an example.)

[1]

51    
52     $\overbracket   {a+b+c+d} \quad \underbracket    {a+b+c+d} \quad
53     \doublebracket{a+b+c+d}$ \blank
54     $\overparent    {a+b+c+d} \quad \underparent     {a+b+c+d} \quad
55     \doubleparent {a+b+c+d}$ \blank
56     $\overbrace     {a+b+c+d} \quad \underbrace      {a+b+c+d} \quad
57     \doublebrace  {a+b+c+d}$ \blank
58     $\overbar       {a+b+c+d} \quad \underbar        {a+b+c+d} \quad
59     \doublebar    {a+b+c+d}$ \blank
60    
61 >>  $\overleftarrow  {a+b+c+d} \quad \overrightarrow  {a+b+c+d} $ \blank
62     $\underleftarrow {a+b+c+d} \quad \underrightarrow {a+b+c+d} $ \blank
63    
64     \stoptext


metapost        > error: unknown, no error, terminal or log messages

tex error       > mp error on line 3 in file /home/fab/ntg80.tex:

>> math_stacker_draw
! Isolated expression.
<to be read again>
(
<*>  math_stacker_draw(
math_stacker_rightarrow_shape) ; ;
I couldn't find an `=' or `:=' after the
expression that is shown above this error message,
so I guess I'll just ignore it and carry on.

! Extra tokens will be flushed.
<to be read again>
(
<*>  math_stacker_draw(
math_stacker_rightarrow_shape) ; ;
I've just read as much of that statement as I could fathom,
so a semicolon should have been next. It's very puzzling...
but I'll try to get myself back together, by ignoring
everything up to the next `;'. Please insert a semicolon
now in front of anything that you don't want me to delete.
(See Chapter 27 of The METAFONTbook for an example.)

[1]

 1    
 2     \useMPlibrary[mat]
 3 >> 
 4     % will be in meta-imp-mat.mkiv
 5    
 6     \startMPextensions
 7          vardef math_stacker_arrow_shape =
 8              image (
 9                  drawarrow
10                      (OverlayWidth,OverlayOffset) -- (0,OverlayOffset)
11                  withcolor
12                      OverlayLineColor ;
13                  setbounds currentpicture to boundingbox currentpicture


metapost        > error: unknown, no error, terminal or log messages
backend         > xmp > using file '/home/fab/context/tex/texmf-context/tex/context/base/mkiv/lpdf-pdx.xml'
pages           > flushing realpage 1, userpage 1, subpage 1
close source    > level 2, order 4, name '/home/fab/ntg80.tex'
close source    > level 1, order 4, name '/home/fab/context/tex/texmf-context/tex/context/base/mkiv/cont-yes.mkiv'

mkiv lua stats  > used config file: selfautoparent:/texmf/web2c/texmfcnf.lua
mkiv lua stats  > used cache path: /home/fab/context/tex/texmf-cache/luatex-cache/context/5fe67e0bfe781ce0dde776fb1556f32e
mkiv lua stats  > resource resolver: loadtime 0.020 seconds, 1 scans with scantime 0.012 seconds, 0 shared scans, 28 found files, scanned paths: /home/fab/texmf
mkiv lua stats  > stored bytecode data: 410 modules (0.227 sec), 93 tables (0.014 sec), 503 chunks (0.241 sec)
mkiv lua stats  > traced context: maxstack: 1287, freed: 4, unreachable: 1283
mkiv lua stats  > cleaned up reserved nodes: 58 nodes, 9 lists of 453
mkiv lua stats  > node memory usage: 2 glue, 2 kern, 2 penalty, 10 attribute, 50 glue_spec, 4 attribute_list, 2 temp, 2 user_defined
mkiv lua stats  > node list callback tasks: 7 unique task lists, 7 instances (re)created, 116 calls
mkiv lua stats  > used backend: pdf (backend for directly generating pdf output)mkiv lua stats  > jobdata time: 0.000 seconds saving, 0.000 seconds loading
mkiv lua stats  > callbacks: 294 direct, 398 indirect, 692 total
mkiv lua stats  > loaded patterns: en::2, load time: 0.000
mkiv lua stats  > result saved in file: ntg80.pdf, compresslevel 3, objectcompresslevel 3
mkiv lua stats  > loaded fonts: 2 files: latinmodern-math.otf, lmroman12-regular.otf
mkiv lua stats  > font engine: otf 3.103, afm 1.513, tfm 1.000, 4 instances, load time 0.115 seconds
mkiv lua stats  > metapost processing time: 0.006 seconds, loading: 0.018, execution: 0.003, n: 8, average: 0.003, instances: 1, memory: 2.519 M
mkiv lua stats  > used platform: linux-64, type: unix, binary subtree: texmf-linux-64
mkiv lua stats  > used engine: luatex version 1.07 with functionality level 6635, banner: this is luatex, version 1.07.0 (tex live 2018)
mkiv lua stats  > control sequences: 46427 of 65536 + 100000
mkiv lua stats  > lua properties: engine: lua 5.3, used memory: 83 MB (ctx: 83 MB), hash type: lua, hash chars: min(64,40), symbol mask: utf (τεχ)
mkiv lua stats  > runtime: 0.457 seconds, 1 processed pages, 1 shipped pages, 2.188 pages/second

mtx-context     | fatal error: return code: 1
TeX Output exited abnormally with code 1 at Thu Mar 22 22:13:31

2018-03-22 9:54 GMT+01:00 Hans Hagen <j.hagen@xs4all.nl>:
---------- Forwarded message ----------
From: Fabrice Couvreur <fabrice1.couvreur@gmail.com>
Date: Tue, Mar 20, 2018 at 4:29 PM
Subject: [NTG-context] Macro to write a vector (Metafun) is broken
To: mailing list for ConTeXt users <ntg-context@ntg.nl>


Hello Hans,
The macro you wrote to draw the arrows of the vectors does not seem to
work anymore.
Thank you
Fabrice

Did you check ou tthe latest meta-imp file? Alan and I added more and also changed the interface a little which might have consequences.

\useMPlibrary[mat]

% will be in meta-imp-mat.mkiv

\startMPextensions
      vardef math_stacker_arrow_shape =
          image (
              drawarrow
                  (OverlayWidth,OverlayOffset) -- (0,OverlayOffset)
              withcolor
                  OverlayLineColor ;
              setbounds currentpicture to boundingbox currentpicture
bottomenlarged (OverlayOffset/2) topenlarged (OverlayOffset/2) ;
          )
      enddef ;
      vardef math_stacker_leftarrow_shape =
          math_stacker_arrow_shape
      enddef ;
      vardef math_stacker_rightarrow_shape =
          math_stacker_arrow_shape rotated 180
      enddef ;
\stopMPextensions

\startuniqueMPgraphic{math:stacker:\number"2190}
      math_stacker_draw(math_stacker_leftarrow_shape) ;
\stopuniqueMPgraphic

\startuniqueMPgraphic{math:stacker:\number"2192}
      math_stacker_draw(math_stacker_rightarrow_shape) ;
\stopuniqueMPgraphic

% so far

\setupmathstackers
    [both] % vfenced]
    [color=darkred,
     alternative=mp]

\setupmathstackers
    [top]
    [color=darkred,
     alternative=mp]

\setupmathstackers
    [bottom]
    [color=darkred,
     alternative=mp]

\starttext

$\overbracket   {a+b+c+d} \quad \underbracket    {a+b+c+d} \quad
\doublebracket{a+b+c+d}$ \blank
$\overparent    {a+b+c+d} \quad \underparent     {a+b+c+d} \quad
\doubleparent {a+b+c+d}$ \blank
$\overbrace     {a+b+c+d} \quad \underbrace      {a+b+c+d} \quad
\doublebrace  {a+b+c+d}$ \blank
$\overbar       {a+b+c+d} \quad \underbar        {a+b+c+d} \quad
\doublebar    {a+b+c+d}$ \blank

$\overleftarrow  {a+b+c+d} \quad \overrightarrow  {a+b+c+d} $ \blank
$\underleftarrow {a+b+c+d} \quad \underrightarrow {a+b+c+d} $ \blank

\stoptext

___________________________________________________________________________________
If your question is of interest to others as well, please add an entry
to the Wiki!

maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
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___________________________________________________________________________________




--

-----------------------------------------------------------------
                                          Hans Hagen | PRAGMA ADE
              Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
       tel: 038 477 53 69 | www.pragma-ade.nl | www.pragma-pod.nl
-----------------------------------------------------------------
___________________________________________________________________________________
If your question is of interest to others as well, please add an entry to the Wiki!

maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
webpage  : http://www.pragma-ade.nl / http://context.aanhet.net
archive  : https://bitbucket.org/phg/context-mirror/commits/
wiki     : http://contextgarden.net
___________________________________________________________________________________