Hello,
Here is the content of my file ~/.profile :

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

$ command -v context
>

 [aragorn@fab ~]$  command -v context
/home/aragorn/texlive/2018/bin/x86_64-linux/context
[aragorn@fab ~]$

I then tested the vladimir.tex file



\setupsynctex[state=start]

\startusableMPgraphic{NumberHead}
  draw outlinetext.f
  ("\bf\namedheadnumber{chapter}")
  (withcolor "blue")
  ysized 50pt ;
\stopusableMPgraphic

\unexpanded\def\processMPheadnumber#1%
  {\useMPgraphic{NumberHead}}

\setuphead%
[chapter]%
[command=\HeadTitle,%
 headstyle=\ss,%
 numbercommand=\processMPheadnumber]

\unexpanded\def\HeadTitle#1#2%
{\framed%
  [frame=off,%
    bottomframe=on,%
    width=broad,
    align={broad,nothyphenated,left}]%
{#1\blank[nowhite]#2}}

\starttext
\startchapter[title=First chapter]
  \input ward
\stopchapter
\stoptext
~/

% Local Variables:
% mode: context
% TeX-master: t
% End:

Here is the output vladimi
r
.output


Running `ConTeXt' on `vladimir' with
``PATH=/home/aragorn/context/tex/texmf-linux-64/bin:$PATH context
--purgeall 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 --c:purgeall
"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: 2018.08.25 10:04 MKIV beta  fmt: 2018.8.25
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'
open source     > level 3, order 4, name
'/home/aragorn/context/tex/texmf-context/tex/context/sample/common/ward.tex'
close source    > level 3, order 4, name
'/home/aragorn/context/tex/texmf-context/tex/context/sample/common/ward.tex'
backend         > xmp > using file
'/home/aragorn/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/aragorn/vladimir.tex'
close source    > level 1, order 4, name
'/home/aragorn/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/aragorn/context/tex/texmf-cache/luatex-cache/context/5fe67e0bfe781ce0dde776fb1556f32e
mkiv lua stats  > resource resolver: loadtime 0.008 seconds, 1 scans with
scantime 0.000 seconds, 0 shared scans, 31 found files, scanned paths:
/home/aragorn/texmf
mkiv lua stats  > stored bytecode data: 437 modules (0.227 sec), 93 tables
(0.015 sec), 530 chunks (0.241 sec)
mkiv lua stats  > traced context: maxstack: 1328, freed: 5, unreachable:
1323
mkiv lua stats  > cleaned up reserved nodes: 58 nodes, 9 lists of 455
mkiv lua stats  > node memory usage: 2 glue, 2 kern, 2 penalty, 14
attribute, 50 glue_spec, 4 attribute_list, 2 temp, 2 user_defined
mkiv lua stats  > node list callback tasks: 8 unique task lists, 6
instances (re)created, 55 calls
mkiv lua stats  > synctex tracing: 2 referenced files, 5 files ignored, 3
objects flushed, logfile: vladimir.synctex
mkiv lua stats  > used backend: pdf (backend for directly generating pdf
output)
mkiv lua stats  > jobdata time: 0.001 seconds saving, 0.000 seconds loading
mkiv lua stats  > callbacks: internal: 177, file: 180, direct: 2, late: 2,
function 534, total: 895
mkiv lua stats  > loaded patterns: en::2, load time: 0.000
mkiv lua stats  > result saved in file: vladimir.pdf, compresslevel 3,
objectcompresslevel 3
mkiv lua stats  > loaded fonts: 4 files: latinmodern-math.otf,
lmroman10-bold.otf, lmroman10-regular.otf, lmroman12-regular.otf
mkiv lua stats  > font engine: otf 3.104, afm 1.513, tfm 1.000, 9
instances, 3 shared in backend, 3 common vectors, 0 common hashes, load
time 0.216 seconds
mkiv lua stats  > metapost: 0.001 seconds, loading: 0.017, execution:
0.001, n: 1, average: 0.019, instances: 1, luacalls: 8, memory: 2.635 M
mkiv lua stats  > used platform: linux-64, type: unix, binary subtree:
texmf-linux-64
mkiv lua stats  > used engine: luatex version 1.08 with functionality level
6731, banner: this is luatex, version 1.08.0 (tex live 2018)
mkiv lua stats  > control sequences: 46537 of 65536 + 100000
mkiv lua stats  > lua properties: engine: lua 5.3, used memory: 81 MB (ctx:
81 MB), hash type: lua, hash chars: min(64,40), symbol mask: utf (τεχ)
mkiv lua stats  > runtime: 0.538 seconds, 1 processed pages, 1 shipped
pages, 1.859 pages/second
mtx-context     | run 2: 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=2 --c:fulljobname="./vladimir"
--c:input="./vladimir" --c:kindofrun=2 --c:maxnofruns=9 --c:purgeall
"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: 2018.08.25 10:04 MKIV beta  fmt: 2018.8.25
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'
open source     > level 3, order 4, name
'/home/aragorn/context/tex/texmf-context/tex/context/sample/common/ward.tex'
close source    > level 3, order 4, name
'/home/aragorn/context/tex/texmf-context/tex/context/sample/common/ward.tex'
backend         > xmp > using file
'/home/aragorn/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/aragorn/vladimir.tex'
close source    > level 1, order 4, name
'/home/aragorn/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/aragorn/context/tex/texmf-cache/luatex-cache/context/5fe67e0bfe781ce0dde776fb1556f32e
mkiv lua stats  > resource resolver: loadtime 0.008 seconds, 1 scans with
scantime 0.001 seconds, 0 shared scans, 31 found files, scanned paths:
/home/aragorn/texmf
mkiv lua stats  > stored bytecode data: 437 modules (0.238 sec), 93 tables
(0.015 sec), 530 chunks (0.253 sec)
mkiv lua stats  > traced context: maxstack: 1328, freed: 5, unreachable:
1323
mkiv lua stats  > cleaned up reserved nodes: 58 nodes, 9 lists of 455
mkiv lua stats  > node memory usage: 2 glue, 2 kern, 2 penalty, 14
attribute, 50 glue_spec, 4 attribute_list, 2 temp, 2 user_defined
mkiv lua stats  > node list callback tasks: 8 unique task lists, 6
instances (re)created, 55 calls
mkiv lua stats  > synctex tracing: 2 referenced files, 5 files ignored, 3
objects flushed, logfile: vladimir.synctex
mkiv lua stats  > used backend: pdf (backend for directly generating pdf
output)
mkiv lua stats  > jobdata time: 0.001 seconds saving, 0.000 seconds loading
mkiv lua stats  > callbacks: internal: 177, file: 180, direct: 2, late: 2,
function 534, total: 895
mkiv lua stats  > randomizer: initialized with value 0.55005725985393
mkiv lua stats  > loaded patterns: en::2, load time: 0.000
mkiv lua stats  > result saved in file: vladimir.pdf, compresslevel 3,
objectcompresslevel 3
mkiv lua stats  > loaded fonts: 4 files: latinmodern-math.otf,
lmroman10-bold.otf, lmroman10-regular.otf, lmroman12-regular.otf
mkiv lua stats  > font engine: otf 3.104, afm 1.513, tfm 1.000, 9
instances, 3 shared in backend, 3 common vectors, 0 common hashes, load
time 0.227 seconds
mkiv lua stats  > metapost: 0.001 seconds, loading: 0.017, execution:
0.001, n: 1, average: 0.019, instances: 1, luacalls: 8, memory: 2.635 M
mkiv lua stats  > used platform: linux-64, type: unix, binary subtree:
texmf-linux-64
mkiv lua stats  > used engine: luatex version 1.08 with functionality level
6731, banner: this is luatex, version 1.08.0 (tex live 2018)
mkiv lua stats  > control sequences: 46536 of 65536 + 100000
mkiv lua stats  > lua properties: engine: lua 5.3, used memory: 81 MB (ctx:
81 MB), hash type: lua, hash chars: min(64,40), symbol mask: utf (τεχ)
mkiv lua stats  > runtime: 0.562 seconds, 1 processed pages, 1 shipped
pages, 1.779 pages/second
mtx-context     | run 3: 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=3 --c:fulljobname="./vladimir"
--c:input="./vladimir" --c:kindofrun=2 --c:maxnofruns=9 --c:purgeall
"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: 2018.08.25 10:04 MKIV beta  fmt: 2018.8.25
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'
open source     > level 3, order 4, name
'/home/aragorn/context/tex/texmf-context/tex/context/sample/common/ward.tex'
close source    > level 3, order 4, name
'/home/aragorn/context/tex/texmf-context/tex/context/sample/common/ward.tex'
backend         > xmp > using file
'/home/aragorn/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/aragorn/vladimir.tex'
close source    > level 1, order 4, name
'/home/aragorn/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/aragorn/context/tex/texmf-cache/luatex-cache/context/5fe67e0bfe781ce0dde776fb1556f32e
mkiv lua stats  > resource resolver: loadtime 0.007 seconds, 1 scans with
scantime 0.000 seconds, 0 shared scans, 31 found files, scanned paths:
/home/aragorn/texmf
mkiv lua stats  > stored bytecode data: 437 modules (0.217 sec), 93 tables
(0.015 sec), 530 chunks (0.232 sec)
mkiv lua stats  > traced context: maxstack: 1328, freed: 5, unreachable:
1323
mkiv lua stats  > cleaned up reserved nodes: 58 nodes, 9 lists of 455
mkiv lua stats  > node memory usage: 2 glue, 2 kern, 2 penalty, 14
attribute, 50 glue_spec, 4 attribute_list, 2 temp, 2 user_defined
mkiv lua stats  > node list callback tasks: 8 unique task lists, 6
instances (re)created, 55 calls
mkiv lua stats  > synctex tracing: 2 referenced files, 5 files ignored, 3
objects flushed, logfile: vladimir.synctex
mkiv lua stats  > used backend: pdf (backend for directly generating pdf
output)
mkiv lua stats  > jobdata time: 0.001 seconds saving, 0.000 seconds loading
mkiv lua stats  > callbacks: internal: 177, file: 180, direct: 2, late: 2,
function 534, total: 895
mkiv lua stats  > randomizer: resumed with value 0.55005725985393
mkiv lua stats  > loaded patterns: en::2, load time: 0.000
mkiv lua stats  > result saved in file: vladimir.pdf, compresslevel 3,
objectcompresslevel 3
mkiv lua stats  > loaded fonts: 4 files: latinmodern-math.otf,
lmroman10-bold.otf, lmroman10-regular.otf, lmroman12-regular.otf
mkiv lua stats  > font engine: otf 3.104, afm 1.513, tfm 1.000, 9
instances, 3 shared in backend, 3 common vectors, 0 common hashes, load
time 0.221 seconds
mkiv lua stats  > metapost: 0.001 seconds, loading: 0.018, execution:
0.001, n: 1, average: 0.019, instances: 1, luacalls: 8, memory: 2.635 M
mkiv lua stats  > used platform: linux-64, type: unix, binary subtree:
texmf-linux-64
mkiv lua stats  > used engine: luatex version 1.08 with functionality level
6731, banner: this is luatex, version 1.08.0 (tex live 2018)
mkiv lua stats  > control sequences: 46536 of 65536 + 100000
mkiv lua stats  > lua properties: engine: lua 5.3, used memory: 86 MB (ctx:
85 MB), hash type: lua, hash chars: min(64,40), symbol mask: utf (τεχ)
mkiv lua stats  > runtime: 0.536 seconds, 1 processed pages, 1 shipped
pages, 1.866 pages/second
mtx-context     | purged files: vladimir.log, vladimir.tuc
system          | total runtime: 2.525 seconds


TeX Output finished at Wed Aug 29 11:54:03

Could you show in full your ~/.emacs file? Do you use AUCTeX or bare
> Emacs
> ?
>

I use AUCTEX but I d not know bare Emacs

(custom-set-variables
 ;; custom-set-variables was added by Custom.
 ;; If you edit it by hand, you could mess it up, so be careful.
 ;; Your init file should contain only one such instance.
 ;; If there is more than one, they won't work right.
 '(ConTeXt-Mark-version "IV")
 '(ConTeXt-engine "luatex")
 '(TeX-command-extra-options "-shell-escape")
 '(ansi-color-faces-vector
   [default default default italic underline success warning error])
 '(ansi-color-names-vector
   ["#242424" "#e5786d" "#95e454" "#cae682" "#8ac6f2" "#333366" "#ccaa8f"
"#f6f3e8"])
 '(custom-enabled-themes (quote (leuven)))
 '(package-selected-packages
   (quote
    (yasnippet-snippets auto-complete-auctex context-coloring nova-theme
auctex)))
 '(tab-width 4))
(custom-set-faces
 ;; custom-set-faces was added by Custom.
 ;; If you edit it by hand, you could mess it up, so be careful.
 ;; Your init file should contain only one such instance.
 ;; If there is more than one, they won't work right.
 )

;; SERVER Download (MELPA):

(when (>= emacs-major-version 24)
  (require 'package)
  (add-to-list
   'package-archives
   '("melpa" . "http://melpa.org/packages/")
   t))


(eval-after-load "context"
  '(setq TeX-command-list
       (cons '("ConTeXt"
"PATH=/home/aragorn/context/tex/texmf-linux-64/bin:$PATH context --purgeall
%s"
         TeX-run-command nil t :help "Run context (MarkIV)")
TeX-command-list))
)


;;(add-hook 'ConTeXt-mode-hook
          ;;(lambda()
          ;;  (setq TeX-command-default "ConTeXt Full")))

(setq-default cursor-type 'bar)

(set-cursor-color "#ff0000")


(setq TeX-view-program-list '(("Evince" "evince %o"))
      TeX-view-program-selection '((output-pdf "Evince")))

(setq make-backup-files nil) ; stop creating backup~ files
(setq auto-save-default nil) ; stop creating #autosave# files

;; auto close bracket insertion. New in emacs 24
(electric-pair-mode 1)

;; turn on highlight matching brackets when cursor is on one
(show-paren-mode 1)


(setq inhibit-startup-screen t)


(add-to-list 'load-path "/home/aragorn/texlive/2018/texmf-dist/asymptote")
(autoload 'asy-mode "asy-mode.el" "Asymptote major mode." t)
(autoload 'lasy-mode "asy-mode.el" "hybrid Asymptote/Latex major mode." t)
(autoload 'asy-insinuate-latex "asy-mode.el" "Asymptote insinuate LaTeX." t)
(add-to-list 'auto-mode-alist '("\\.asy$" . asy-mode))

(setq column-number-mode t)

(setq line-number-mode t)


(setq py-install-directory "~/.emacs.d/site-lisp/python-mode.el-6.1.1")

(add-to-list 'load-path py-install-directory)

(require 'python-mode)

;;(add-hook 'ConTeXt-mode-hook
          ;;(lambda ()
           ;; (setq indent-tabs-mode t
                ;;  indent-line-function 'indent-relative)))

(add-hook 'LaTeX-mode-hook
          (lambda()
             (add-to-list 'TeX-command-list '("LuaTeX" "%`lualatex%(mode)%'
%t" TeX-run-TeX nil t))
             (setq TeX-command-default "LuaTeX")
             (setq TeX-save-query nil)
             (setq TeX-show-compilation t)))


(setq-default TeX-engine 'luatex
              TeX-PDF-mode t)
Thanks
Fabrice


Le mer. 29 août 2018 à 11:39, Fabrice Couvreur <fabrice1.couvreur@gmail.com>
a écrit :

> Hello,
> Before considering modifications, here's what I get when I do which
> context :
>
> Setting "/home/aragorn/context/tex" as ConTeXt root.
> [aragorn@fab ~]$ which context
> /home/aragorn/context/tex/texmf-linux-64/bin/context
> [aragorn@fab ~]$
>
> $ pacman -Qs texlive
>>
>
>  [root@fab aragorn]# pacman -Qs texlive
> [root@fab aragorn]#
>
> $ pacman -Qs emacs
>>
>
>  [root@fab aragorn]# pacman -Qs emacs
> local/emacs 26.1-2
>     The extensible, customizable, self-documenting real-time display editor
> local/emacs-python-mode 6.2.3-1
>     Python mode for Emacs
> [root@fab aragorn]#
>
> you mentioned that commands run in terminal worked fine, but you
>>   invoked them by full path;
>>
>
>
> To be able to test with the
> texlive context binary and context standalone context binary
> .
>
>
> The next in the next message after restarting my PC ...
>
> Fabrice
>
>
> Le mer. 29 août 2018 à 04:58, Vladimir Lomov <lomov.vl@yandex.ru> a
> écrit :
>
>> Hello,
>> ** Fabrice Couvreur [2018-08-28 11:18:58 +0200]:
>>
>> > Hi Vladimir,
>>
>> > I do not use Arch Linux repositories to install  texlive 2018 packages
>>
>> Some texlive-* packages could be installed as dependencies of other
>> packages. You may check if your system has any texlive package:
>>
>>   $ pacman -Qs texlive
>>
>> > but I installed texlive 2018 "scheme-full" with tlmgr -gui  in
>> > /home/aragorn /texlive/2018.  I then make regular updates in the same
>> > way. No texlive traces in the \usr\share\ directory or elsewhere.
>>
>> I prefer to rely on package manager.
>>
>> > Standalone Context is also installed in my home directory. However,
>> > Emacs is installed from the Arch Linux repositories and is located in
>> > /usr/share/emacs.
>>
>>   $ pacman -Qs emacs
>>
>> > So I have to add the path of texlive 2018 ?
>> > Maybe you do not need to add the Context Standalone path ?
>> > My ~/.profile file would be this :
>> >
>> > source /home/aragorn/context/tex/setuptex
>> > export PATH = $ PATH: /home/aragorn/texlive/2018/bin/x86_64-linux
>> > export PATH = $ PATH: /home/aragorn /bin
>>
>> This part is a bit strange:
>> - in message
>>   https://mailman.ntg.nl/pipermail/ntg-context/2018/092418.html
>>   you mentioned that commands run in terminal worked fine, but you
>>   invoked them by full path;
>>
>> - in the same message you set PATH in emacs as
>>
>>     (setenv "PATH" "/home/aragorn/context/tex/texmf-linux-64/bin/:$PATH"
>> t)
>>
>>   (I have to admit that I didn't know it is possible to use '$PATH' in
>>   setenv), so it prepends path to context binary to PATH list. The above
>>   lines do opposite: they append path to context binary to the end of
>>   PATH list.
>>
>>   The first line, 'source ...', helps here because 'setuptex' in turns
>>   prepend path to context binary to PATH.
>>
>> When you invoke 'context' in terminal (I assume it is bash shell) the
>> shell searches program in current directory (depends on configuration)
>> and then in PATH, the first wins. So to use context from ConTeXt
>> standalone you may simply do
>>
>>   $ export PATH=$HOME/context/tex/texmf-linux-64/bin:$PATH
>>
>> either in terminal or in ~/.profile. You may always check if this is
>> true by runnig
>>
>>   $ command -v context
>>
>> (for bash shell) or
>>
>>   $ which context
>>
>> Returning to your problem. I looked closely again in messages with
>> output from context and I don't understand what may cause the error.
>> Seems that Emacs uses correct context (according to loading files).
>> Could you show in full your ~/.emacs file? Do you use AUCTeX or bare
>> Emacs?
>>
>> > Regards,
>> > Fabrice
>> >
>>
>> [...]
>>
>> ---
>> WBR, Vladimir Lomov
>>
>>
>> --
>> Uncontrolled power will turn even saints into savages.  And we can all
>> be counted on to live down to our lowest impulses.
>>                 -- Parmen, "Plato's Stepchildren", stardate 5784.3
>>
>> ___________________________________________________________________________________
>> 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
>>
>> ___________________________________________________________________________________
>
>