Hi Vladimir,
I use ConTeXt Full following this question asked on the forum https://mailman.ntg.nl/pipermail/ntg-context/2017/089501.html
Then, if I compile with ConTeXt, the problem is not solved and the file vladimir.log is empty !
This is the buffer vladimir.output with emacs

-------------------------------- 8< ----------------------------------------------------------------------------------------------------------------------------------------------
Running `ConTeXt' on `vladimir' with ``PATH=/home/aragorn/context/tex/texmf-linux-64/bin:$PATH context vladimir''
resolvers       | trees | analyzing 'home:texmf'
mtx-context     | warning: no (local) file './vladimir', proceeding
mtx-context     | run 1: luatex --fmt="/home/aragorn/context/tex/texmf-cache/luatex-cache/context/5fe67e0bfe781ce0dde776fb1556f32e/formats/luatex/cont-en" --jobname="vladimir" --lua="/home/aragorn/context/tex/texmf-cache/luatex-cache/context/5fe67e0bfe781ce0dde776fb1556f32e/formats/luatex/cont-en.lui" --no-parse-first-line --c:currentrun=1 --c:fulljobname="./vladimir" --c:input="./vladimir" --c:kindofrun=1 --c:maxnofruns=9 "cont-yes.mkiv"

This is LuaTeX, Version 1.08.0 (TeX Live 2018)
 system commands enabled.

resolvers       > trees > analyzing 'home:texmf'
open source     > level 1, order 1, name '/home/aragorn/context/tex/texmf-context/tex/context/base/mkiv/cont-yes.mkiv'
system          >
system          > ConTeXt  ver: 2018.08.20 17:47 MKIV beta  fmt: 2018.8.20  int: english/english
system          >
system          > 'cont-new.mkiv' loaded
open source     > level 2, order 2, name '/home/aragorn/context/tex/texmf-context/tex/context/base/mkiv/cont-new.mkiv'
system          > beware: some patches loaded from cont-new.mkiv
close source    > level 2, order 2, name '/home/aragorn/context/tex/texmf-context/tex/context/base/mkiv/cont-new.mkiv'
system          > files > jobname 'vladimir', input './vladimir', result 'vladimir'
fonts           > latin modern fonts are not preloaded
languages       > language 'en' is active
open source     > level 2, order 3, name '/home/aragorn/vladimir.tex'
system          > synctex functionality is enabled, expect 5-10 pct runtime overhead!
fonts           > preloading latin modern fonts (second stage)
fonts           > 'fallback modern-designsize rm 12pt' is loaded
structure       > sectioning > chapter @ level 2 : 0.1 -> First chapter
metapost        > initializing instance 'metafun:1' using format 'metafun' and method 'default'
metapost        > loading 'metafun' as '/home/aragorn/context/tex/texmf-context/metapost/context/base/mpiv/metafun.mpiv' using method 'default'
metapost        > initializing number mode 'scaled'

lua error       > lua error on line 10 in file /home/aragorn/vladimir.tex:

...ext/tex/texmf-context/tex/context/base/mkiv/node-nut.lua:190: attempt to call a nil value (global 'getid')
stack traceback:
    ...ext/tex/texmf-context/tex/context/base/mkiv/node-nut.lua:190: in upvalue 'getexpansion'
    ...ext/tex/texmf-context/tex/context/base/mkiv/font-mps.lua:343: in function <...ext/tex/texmf-context/tex/context/base/mkiv/font-mps.lua:338>
    ...ext/tex/texmf-context/tex/context/base/mkiv/font-mps.lua:437: in local 'boxtomp'
    ...ext/tex/texmf-context/tex/context/base/mkiv/mlib-pps.lua:1894: in function <...ext/tex/texmf-context/tex/context/base/mkiv/mlib-pps.lua:1891>
    (...tail calls...)

 1    
 2     \setupsynctex[state=start]
 3    
 4     \startusableMPgraphic{NumberHead}
 5       draw outlinetext.f
 6       ("\bf\namedheadnumber{chapter}")
 7       (withcolor "red")
 8       ysized 50pt ;
 9     \stopusableMPgraphic
10 >> 
11     \unexpanded\def\processMPheadnumber#1%
12       {\useMPgraphic{NumberHead}}
13    
14     \setuphead%
15     [chapter]%
16     [command=\HeadTitle,%
17      headstyle=\ss,%
18      numbercommand=\processMPheadnumber]
19    
20     \unexpanded\def\HeadTitle#1#2%


?
-------------------------------- 8< -------------------------------------------------------------------------------------------------------------------------------------------------------------
But if I compile from a terminal without using emacs it works !

[aragorn@fab ~]$ /home/aragorn/context/tex/texmf-linux-64/bin/context vladimir.tex

Are we sure it is context standalone that is used by emacs rather than context texlive 2018 ?
When reading the file vladimir.log, I doubt a little ...
Thanks
Fabrice

PS : Here is the content of the file ~/.profile :

export PATH=$PATH:/home/aragorn/context/tex/texmf-linux-64/bin/context
export PATH=$PATH:/home/aragorn/texlive/2018/bin/x86_64-linux
export PATH=$PATH:/home/aragorn/bin

Le ven. 24 août 2018 à 15:48, Vladimir Lomov <lomov.vl@yandex.ru> a écrit :
Hello,
** Fabrice Couvreur [2018-08-24 12:31:19 +0200]:

> Hi Vladimir,
> Thanks for everything, it seems to work !

> You are the only one who knew how to solve the problem.

> Here is the content of my ~./emacs file that you probably need to improve :
>
> -------------------------------- 8< ---------------------------------
>
> (eval-after-load "context"
>   '(setq TeX-command-list
>      (cons '("ConTeXt"
> "PATH=/home/aragorn/context/tex/texmf-linux-64/bin:$PATH context %s"
>        TeX-run-command nil t :help "Run context (MarkIV)")
> TeX-command-list))
> )
>
> (setq ConTeXt-mode-hook
>       (lambda () (setq TeX-command-extra-options "--purgeall")))
>
>
> (add-hook 'ConTeXt-mode-hook
>           (lambda()
>             (setq TeX-command-default "ConTeXt Full")))

Why did you set "ConTeXt Full" as your default command? The above
'setq' introduces "ConTeXt" command to process a context file. When I
said that everything is OK I meant that I did C-c C-c, checked that in
minibuffer the "ConTeXt" command is chosen and then hit Enter.

> -------------------------------- 8< ---------------------------------
>
> By cons if I add this :
>
> -------------------------------- 8< ---------------------------------
>
> (setenv "TEXMFCNF" nil)
> (setenv "TEXROOT" "/home/aragorn/context/tex")
> (setenv "TEXMFCACHE" (format "%s/.cache" (getenv "HOME")))
>
>
> -------------------------------- 8< ---------------------------------
>
>
>  the compilation returns a damaged pdf file that I can not open.

I don't know why you get "damaged" pdf file (in fact how do you know
that file is damaged?) but "TEXMFCNF" is special variable that I uses to
tweak TeX Live configuration for my latex workflow but context
(standalone and from TL) refuses to work if this variable is set (in
terminal I do 'unset' while in Emacs I set its value to 'nil' because
this is identical to "unset" it). The "TEXROOT" variable I found in
update script, I'm not sure if context requires it to work but IMHO, it
is harmless. And the last variable "TEXMFCACHE" I use to force context
to use ~/.cache for "luatex-cache" directory and not "pollute" my home
directory (without it the "luatex-cache" directory will be created in
$HOME directory).

> I installed texlive 2018 and context standalone in my home directory and
> emacs in the /usr/share/emacs directory with Arch Linux ; can that explain
> my problems ?

Not sure but I'll wait you answer about "ConTeXt Full" vs "ConTeXt" I
mentioned above.

> Fabrice

[...]

---
WBR, Vladimir Lomov

--
I'm serious about thinking through all the possibilities before we
settle on anything.  All things have the advantages of their
disadvantages, and vice versa.
             -- Larry Wall in <199709032332.QAA21669@wall.org>
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