How do I debug Error spawn ENOENT on node js

Question

When I get the following error   events js 72         throw er     Unhandled  error  event                 Error  spawn ENOENT     at errnoException  child process js 1000 11      at Process ChildProcess  handle onexit  child process js 791 34    What procedure can I follow to fix it   Author note  Lots of issues with this error encouraged me to post this question for future references   Related questions    using spawn function with NODE ENV production node js child process spawn ENOENT error - only under supervisord spawn ENOENT node js error https   stackoverflow com questions 27603713 nodejs-spawn-enoent-error-on-travis-calling-global-npm-package Node JS - child process spawn   39 npm install  39   in Grunt task results in ENOENT error Running  quot foreman quot  task Fatal error  spawn ENOENT unhandled error event in node js Error  spawn ENOENT at errnoException  child process js 975 11  Node js SpookyJS  error executing hello js https   stackoverflow com questions 26572214 run-grunt-on-a-directory-nodewebkit Run exe file with Child Process NodeJS Node  child process spawn not working on Java even though it  39 s in the path  ENOENT  spawn ENOENT error with NodeJS  PYTHON related  image resizing is not working in node js  partial js   non-installed dependency  npm install error ENOENT  build dependency problem  Cannot install node js - oracle module on Windows 7  build dependency problem  Error installing gulp using nodejs on windows  strange case

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Although it may be an environment path or another issue for some people  I had just installed the Latex Workshop extension for Visual Studio Code on Windows 10 and saw this error when attempting to build preview the PDF  Running VS Code as Administrator solved the problem for me

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solution in my case   var spawn   require  child process   spawn   const isWindows     win  test process platform     spawn isWindows    twitter-proxy cmd     twitter-proxy    spawn isWindows    http-server cmd     http-server

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Step 1  Ensure spawn is called the right way  First  review the docs for child process spawn  command  args  options        Launches a new process with the given command  with command line arguments in args  If omitted  args defaults to an empty Array       The third argument is used to specify additional options  which defaults to         cwd  undefined  env  process env        Use env to specify environment variables that will be visible to the new process  the default is process env    Ensure you are not putting any command line arguments in command and the whole spawn call is valid  Proceed to next step   Step 2  Identify the Event Emitter that emits the error event  Search on your source code for each call to spawn  or child process spawn  i e   spawn  some-command      --help        and attach there an event listener for the  error  event  so you get noticed the exact Event Emitter that is throwing it as  Unhandled   After debugging  that handler can be removed   spawn  some-command      --help        on  error   function  err    throw err        Execute and you should get the file path and line number where your  error  listener was registered  Something like    file that registers the error listener js 29       throw err                Error  spawn ENOENT     at errnoException  child process js 1000 11      at Process ChildProcess  handle onexit  child process js 791 34    If the first two lines are still  events js 72         throw er     Unhandled  error  event   do this step again until they are not  You must identify the listener that emits the error before going on next step   Step 3  Ensure the environment variable  PATH is set  There are two possible scenarios    You rely on the default spawn behaviour  so child process environment will be the same as process env  You are explicity passing an env object to spawn on the options argument    In both scenarios  you must inspect the PATH key on the environment object that the spawned child process will use   Example for scenario 1     inspect the PATH key on process env console log  process env PATH    spawn  some-command     --help       Example for scenario 2  var env   getEnvKeyValuePairsSomeHow       inspect the PATH key on the env object console log  env PATH    spawn  some-command     --help      env  env       The absence of PATH  i e   it s undefined  will cause spawn to emit the ENOENT error  as it will not be possible to locate any command unless it s an absolute path to the executable file   When PATH is correctly set  proceed to next step  It should be a directory  or a list of directories  Last case is the usual   Step 4  Ensure command exists on a directory of those defined in PATH  Spawn may emit the ENOENT error if the filename command  i e   some-command   does not exist in at least one of the directories defined on PATH   Locate the exact place of command  On most linux distributions  this can be done from a terminal with the which command  It will tell you the absolute path to the executable file  like above   or tell if it s not found   Example usage of which and its output when a command is found   gt  which some-command some-command is  usr bin some-command   Example usage of which and its output when a command is not found   gt  which some-command bash  type  some-command  not found   miss-installed programs are the most common cause for a not found command  Refer to each command documentation if needed and install it   When command is a simple script file ensure it s accessible from a directory on the PATH  If it s not  either move it to one or make a link to it   Once you determine PATH is correctly set and command is accessible from it  you should be able to spawn your child process without spawn ENOENT being thrown

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I ran into the same problem  but I found a simple way to fix it  It appears to be spawn   errors if the program has been added to the PATH by the user  e g  normal system commands work    To fix this  you can use the which module  npm install --save which       Require which and child process const which   require  which    const spawn   require  child process   spawn     Find npm in PATH const npm   which sync  npm       Execute const noErrorSpawn   spawn npm    install

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Use require  child process   exec instead of spawn for a more specific error message    for example   var exec   require  child process   exec  var commandStr    java -jar something jar    exec commandStr  function error  stdout  stderr      if error    stderr  console log error    stderr     else console log stdout

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In my case removing node  delete all AppData Roaming npm and AppData Roaming npm-cache and installing node once again solve the issue

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I got the same error for windows 8 The issue is because of an environment variable of your system path is missing   Add  C  Windows System32   value to your system  PATH variable

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I ran into this problem on Windows  where calling exec and spawn with the exact same command  omitting arguments  worked fine for exec  so I knew my command was on  PATH   but spawn would give ENOENT  Turned out that I just needed to append  exe to the command I was using   import   exec  spawn   from  child process       This works fine exec  p4 changes -s submitted        This gives the ENOENT error spawn  p4        But this resolves it spawn  p4 exe       Even works with the arguments now spawn  p4 exe     changes    -s    submitted

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laconbass s answer helped me and is probably most correct   I came here because I was using spawn incorrectly  As a simple example   this is incorrect   const s   cp spawn  npm install -D suman             cwd  root       this is incorrect   const s   cp spawn  npm     install -D suman          cwd  root       this is correct   const s   cp spawn  npm     install   -D   suman          cwd  root       however  I recommend doing it this way   const s   cp spawn  bash    s stdin end  cd    root    amp  amp  npm install -D suman    s once  exit   code   gt          exit       this is because then the cp on  exit   fn  event will always fire  as long as bash is installed  otherwise  the cp on  error   fn  event might fire first  if we use it the first way  if we launch  npm  directly

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Windows solution  Replace spawn with node-cross-spawn  For instance like this at the beginning of your app js    function         var childProcess   require  child process        childProcess spawn   require  cross-spawn

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NOTE  This error is almost always caused because the command does not exist  because the working directory does not exist  or from a windows-only bug   I found a particular easy way to get the idea of the root cause of   Error  spawn ENOENT   The problem of this error is  there is really little information in the error message to tell you where the call site is  i e  which executable command is not found  especially when you have a large code base where there are a lot of spawn calls  On the other hand  if we know the exact command that cause the error then we can follow  laconbass  answer to fix the problem   I found a very easy way to spot which command cause the problem rather than adding event listeners everywhere in your code as suggested in  laconbass  answer  The key idea is to wrap the original spawn call with a wrapper which prints the arguments send to the spawn call   Here is the wrapper function  put it at the top of the index js or whatever your server s starting script    function         var childProcess   require  child process        var oldSpawn   childProcess spawn      function mySpawn             console log  spawn called            console log arguments           var result   oldSpawn apply this  arguments           return result            childProcess spawn   mySpawn          Then the next time you run your application  before the uncaught exception s message you will see something like that   spawn called    0    hg      1          2        cwd      omitted           env    IP   0 0 0 0          args           In this way you can easily know which command actually is executed and then you can find out why nodejs cannot find the executable to fix the problem

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For anyone who might stumble upon this  if all the other answers do not help and you are on Windows  know that there is currently a big issue with spawn on Windows and the PATHEXT environment variable that can cause certain calls to spawn to not work depending on how the target command is installed

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Ensure module to be executed is installed or full path to command if it s not a node module

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As  DanielImfeld pointed it  ENOENT will be thrown if you specify  cwd  in the options  but the given directory does not exist

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Add C  Windows System32  to the path environment variable   Steps   Go to my computer and properties Click on Advanced settings Then on Environment variables Select Path and then click on edit  Paste the following if not already present  C  Windows System32  Close the command prompt  Run the command that you wanted to run

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How to research the spawn call raising the error   Use NODE DEBUG child process  Credits to  karl-richter  Simple  quick  October 2019 Use a wrapper to decorate child process spawn  Credits to  jiaji-zhou  Simple  quick  January 2015 Long procedure  credits to  laconbass  Complex  time-cost  December 2014  Known  usual causes  Environment issues  The command executable does not exist within the system  dependency not being installed   see prominc s answer The command executable does not exist within a directory of those specified by PATH environment variable    Windows-only bugs quirks    cmd  extension   shell  true  see li-zheng answer Administrator permisions  see steve s answer   Wrong spawn  command     --argument    list      cwd  env     opts    usage  Specified working directory  opts cwd  does not exist    see leeroy-brun s answer Argument list within command String spawn  command --wrong --argument list   Env vars within command string spawn  ENV VAR WRONG command   Argument list Array specified as String spawn  cmd    --argument list   Unset PATH env variable spawn  cmd         env    variable       gt  spawn  cmd         env       process env  variable          There are 2 posible origins for ENOENT   Code you are writing Code you depend on  When origin is code you depend on  usual cause is an Environment Issue  or windows quirk

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Are you changing the env option   Then look at this answer     I was trying to spawn a node process and TIL that you should spread the existing environment variables when you spawn else you ll loose the PATH environment variable and possibly other important ones   This was the fix for me   const nodeProcess   spawn  node     --help        env           by default  spawn uses  process env  for the value of  env         you can  add  to this behavior  by spreading  process env         process env      OTHER ENV VARIABLE   test

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I was getting this error when trying to debug a node js program from within VS Code editor on a Debian Linux system  I noticed the same thing worked OK on Windows  The solutions previously given here weren t much help because I hadn t written any  spawn  commands  The offending code was presumably written by Microsoft and hidden under the hood of the VS Code program   Next I noticed that node js is called node on Windows but on Debian  and presumably on Debian-based systems such as Ubuntu  it s called nodejs  So I created an alias - from a root terminal  I ran   ln -s  usr bin nodejs  usr local bin node  and this solved the problem  The same or a similar procedure will presumably work in other cases where your node js is called nodejs but you re running a program which expects it to be called node  or vice-versa

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In my case  I was getting this error thrown due to the necessary dependent system resources not being installed   More specifically  I have a NodeJS app that is utilizing ImageMagick   Despite having the npm package installed  the core Linux ImageMagick was not installed   I did an apt-get to install ImageMagick and after that all worked great

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For ENOENT on Windows  https   github com nodejs node-v0 x-archive issues 2318 issuecomment-249355505 fix it   e g  replace spawn  npm     -v     stdio   inherit    with    for all node js version   spawn   win  test process platform     npm cmd     npm     -v     stdio   inherit     for node js 5 x and later   spawn  npm     -v     stdio   inherit   shell  true

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Before anyone spends to much time debugging this problem  most of the time it can be resolved by deleting node modules and reinstalling the packages  To Install  If a lockfile exists you might use yarn install --frozen-lockfile  or npm ci  respectivly  if not then yarn install  or npm i

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I was also going through this annoying problem while running my test cases  so I tried many ways to get across it  But the way works for me is to run your test runner from the directory which contains your main file which includes your nodejs spawn function something like this   nodeProcess   spawn  node  params   cwd         node    detached  true       For example  this file name is test js  so just move to the folder which contains it  In my case  it is test folder like this   cd root test    then from run your test runner in my case its mocha so it will be like this   mocha test js   I have wasted my more than one day to figure it out  Enjoy

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in windows  simply adding shell  true option solved my problem   incorrect   const   spawn     require  child process    const child   spawn  dir      correct   const   spawn     require  child process    const child   spawn  dir        shell  true

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If you re on Windows Node js does some funny business when handling quotes that may result in you issuing a command that you know works from the console  but does not when run in Node  For example the following should work   spawn  ping      8 8 8 8            but fails  There s a fantastically undocumented option windowsVerbatimArguments for handling quotes similar that seems to do the trick  just be sure to add the following to your opts object   const opts         windowsVerbatimArguments  true      and your command should be back in business    spawn  ping      8 8 8 8       windowsVerbatimArguments  true

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In case you re experiencing this issue with an application whose source you cannot modify consider invoking it with the environment variable NODE DEBUG set to child process  e g  NODE DEBUG child process yarn test  This will provide you with information which command lines have been invoked in which directory and usually the last detail is the reason for the failure

[node.js] How do I debug "Error: spawn ENOENT" on node.js?

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