Passing empty environment variables to child processes convert to 'undefined' using ConEmu + Node #14593

nicojs · 2017-08-02T06:53:53Z

Version: Since Node 8.0.0. (tested in Node 7.9, Node 8.0.0 and Node 8.2.1)
Platform: Windows 10 version 1703 x64 using a shell (cmd.exe or git-bash) in ConEmu

Problem description

When executing a process which spawns a child process, which in turn creates another child process, the empty environment variables are passed through as 'undefined' (the string literal, NOT an absent value). If you than for example do an npm install command from that child process, bad things happen:

npm WARN invalid config access=undefined
npm WARN invalid config also=undefined
npm WARN invalid config https-proxy=undefined
npm WARN invalid config Must be a full url with \'http://\'
npm WARN onload-script     at Function.Module._resolveFilename (module.js:485:15)
npm WARN onload-script  { Error: Cannot find module \'undefined\'

To my knowledge: this only happens in ConEmu, a popular console emulator on Windows. When i downgrade to node 7.9, this problem does not occur.

Steps to reproduce

I created a small github repo to reproduce the problem.

On windows 10: install ConEmu: https://conemu.github.io/
Clone this repo git clone git@github.com:nicojs/reproduce-conemu-child-process-environment-bug.git
run npm install.
run npm test

This test spawns a child process, which in turn starts a new child process which logs the process.env to console. The tests verifies that npm_config_onload_script (one of the env variables) is set to ''.

Actual results

When ran from within ConEmu: the test failes

the env should contain "npm_config_onload_script":
Error: "npm_config_onload_script": "undefined"!"

The test also prints the environment variables to screen. You can see a lot of "undefined" values (the string literal, not an absent value).

For example: "npm_config_onload_script": "undefined",

Expected results

If ran from cmd or git-bash using mintty directly (or on a POSIX environment): the test passes

√ should contain "npm_config_onload_script"

If you now look at the environment variables on screen, you don't see the "undefined" values. Just empty strings.

For example: "npm_config_onload_script": "",

I reported this issue to ConEmu first, but the developer pointed out to me that this seems to be regression in node. See the discussion with Maximus5 here: Maximus5/ConEmu#1209

Screenshots:

ConEmu with cmd.exe shell

Command prompt with cmd.exe shell

The text was updated successfully, but these errors were encountered:

bnoordhuis · 2017-08-02T07:28:06Z

Thanks for the bug report. Does it reproduce outside of npm? The behavior of process.env hasn't changed between v7.x and v8.x so I expect it's caused by something in npm.

nicojs · 2017-08-02T07:49:43Z

I've thought of that as well, but I'm using npm 5.3.0 in all cases so that doesn't seem to be the issue.

Maybe something changed to 'child_process'? I'm using require('child_process').exec and require('child_process').execSync.

bnoordhuis · 2017-08-02T07:54:11Z

Can you reproduce without npm being involved? If so, can you post that test case? (It's fine to do that inline here in a comment.)

nicojs · 2017-08-02T08:17:02Z

Hmm good point.

Yes, I can. In one simple script using node -e.

// start.js
const execSync = require('child_process').execSync;
process.env.foobar = '';
const stdout = execSync('node -e "const execSync = require(\'child_process\').execSync;' +
    'execSync(\'node -e "console.log(process.env.foobar);"\', { stdio: [0, 1, 2]});"')
    .toString().trim();
if (stdout === '') {
    console.log('foobar is empty, stuff works.');
} else {
    console.error(`foobar was "${stdout}", using ConEmu?`);
}

If i run that script from a ConEmu tap using cmd shell it says:

> node start.js
foobar was "undefined", using ConEmu?

From command prompt and cmd.exe:

>node start.js
foobar is empty, stuff works.

bnoordhuis · 2017-08-02T08:30:43Z

Well, that does point to ConEmu. FWIW, it works in the expected way on Linux and OS X too.

nicojs · 2017-08-02T08:50:03Z

Well, that does point to ConEmu. FWIW, it works in the expected way on Linux and OS X too.

ConEmu maintainer Maximus5 says it does not change any environment variables. Also, it is translated to the actual string value 'undefined'. This seems to be something that happens in the JavaScript world.

If you change my script to print the entire environment like this:

const execSync = require('child_process').execSync;
process.env.foobar = '';
const stdout = execSync('node -e "require(\'child_process\').execSync(\'node -e "console.log(process.env);"\', { stdio: [0, 1, 2]});"')
    .toString().trim();
console.log(stdout);

If i run that script from a ConEmu tap it says:

> node start.js
...
foobar: 'undefined',
...

From cmd.exe:

>node start.js
...
foobar: undefined,
...

bnoordhuis · 2017-08-02T09:00:39Z

Can't reproduce, I'm afraid; it prints foobar: '', for me.

cc @nodejs/platform-windows in case any of you can reproduce.

nicojs · 2017-08-02T09:13:02Z

Just double checking: you have Node version 8.0.0 or 8.2.1 and running from inside ConEmu with cmd shell?

Did you let it print the entire process.env (my second inline sample)? In that case it should not print foobar: '', instead it should print foobar: undefined (but from ConEmu it prints foobar: 'undefined'). I've just tested it on an other windows 10 machine with ConEmu and was able to reproduce it using node version 8.1.2.

tniessen · 2017-08-02T09:41:13Z

Unable to reproduce with ConEmu 161206 (stable build) and node 8.2.1 on Windows 10. Both npm install in your repository and your snippet work just fine. Which ConEmu version are you using? How is your shell inside ConEmu configured? Please post the full shell command line along with any additional options.

nicojs · 2017-08-02T12:55:44Z

170402 (preview), but just now also installed 161206 and same issue.

These are my ConEmu settings, but also tried on an other laptop with default settings: https://gist.github.com/nicojs/3abd0b4b2a996c1633bd97c9fd33ec27

See this screenshot for a side by side comparison of what i'm doing. On the left you can see the content of the file "start.js" (which is the first code snippet i shared) and executed from within ConEmu. On the right site you can see the same file executed from command prompt. Also on screen is the about window of ConEmu (with the version).

EDIT:

These are my shell settings for cmd (which are default). But i can reproduce with all shells. Tested with gitbash, powershell and cmd (64bits and 32bits)

bzoz · 2017-08-02T13:02:09Z

@nicojs, could you provide output of env from both ConEmu and cmd.exe?

bzoz · 2017-08-02T13:03:33Z

And node -e console.log(process.env)?

nicojs · 2017-08-02T13:12:08Z

I feel slightly naked for doing this. Everything for the cause. Please don't make fun of the size of my P...ATH

https://gist.github.com/nicojs/4de5af23fa937deb8372ced562ef0878

I did the same thing on both console applications and output can be found in the gist:

> type start.js
> node start.js
> SET
> node -e "console.log(process.env)"

refack · 2017-08-02T13:14:39Z

I can repro:
node - v8.1.3
windows 10x64 build 15063
ConEmu 170517x64
ConEmu shell - cmd.exe /k "%ConEmuBaseDir%\CmdInitRef.cmd" -new_console:a

CmdInitRef.cmd

@rem !!! Do not change this file in-place, change its copy instead !!!
@rem !!!  Otherwise you will lose your settings after next update  !!!

@echo off

rem Simple "ver" prints empty line before Windows version
rem Use this construction to print just a version info
cmd /d /c ver | "%windir%\system32\find.exe" "Windows"

rem Now we form the command prompt

rem This will start prompt with `User@PC `
rem set ConEmuPrompt0=$E[m$E[32m$E]9;8;"USERNAME"$E\@$E]9;8;"COMPUTERNAME"$E\$S
set ConEmuPrompt0=

rem Followed by colored `Path`
set ConEmuPrompt1=%ConEmuPrompt0%$P
if NOT "%PROCESSOR_ARCHITECTURE%" == "AMD64" (
  if "%PROCESSOR_ARCHITEW6432%" == "AMD64" if "%PROCESSOR_ARCHITECTURE%" == "x86" (
    rem Use another text color if cmd was run from SysWow64
    set ConEmuPrompt1=%ConEmuPrompt0%$P
  )
)

rem Carriage return and `$` or `>`
rem Spare `$E[90m` was specially added because of GitShowBranch.cmd
if "%ConEmuIsAdmin%" == "ADMIN" (
  set ConEmuPrompt2=$$
) else (
  set ConEmuPrompt2=$G
)

rem Finally reset color and add space
set ConEmuPrompt3=$S

if /I "%~1" == "/git" goto git
if /I "%~1" == "-git" goto git
goto no_git

:git
call "%~dp0GitShowBranch.cmd" /i
goto :EOF

:no_git
rem Set new prompt
PROMPT %ConEmuPrompt1%%ConEmuPrompt2%%ConEmuPrompt3%

refack · 2017-08-02T13:23:12Z

feel slightly naked for doing this. Everything for the cause. Please don't make fun of the size of my P...ATH

We're all friends here...

Procmon output:

child (node) 4640

High Resolution Date & Time:	02/08/2017 09:17:07.5786824
Event Class:	Process
Operation:	Process Start
Result:	SUCCESS
Path:	
TID:	10428
Duration:	0.0000000
Parent PID:	4640
Command line:	node  -e "const execSync = require('child_process').execSync;execSync('node -e "console.log(process.env.foobar);"', { stdio: [0, 1, 2]});"
Current directory:	d:\code\4node\
Environment:	
	=D:=d:\code\4node
	ALLUSERSPROFILE=C:\ProgramData
	ANSICON=182x10000 (182x51)
	ANSICON_DEF=7
	APPDATA=d:\refael\AppData\Roaming
	CommonProgramFiles=C:\Program Files\Common Files
	CommonProgramFiles(x86)=C:\Program Files (x86)\Common Files
	CommonProgramW6432=C:\Program Files\Common Files
	COMPUTERNAME=REFAELUX
	ComSpec=C:\WINDOWS\System32\cmd.exe
	ConEmuANSI=ON
	ConEmuAnsiLog=
	ConEmuArgs=/dir "d:\code\node"
	ConEmuArgs2=
	ConEmuBackHWND=0x00060A5A
	ConEmuBaseDir=C:\Tools\maint\conemu\ConEmu
	ConEmuBuild=170517
	ConEmuConfig=
	ConEmuDir=C:\Tools\maint\conemu
	ConEmuDrawHWND=0x00060A22
	ConEmuDrive=C:
	ConEmuHooks=Enabled
	ConEmuHWND=0x000606E4
	ConEmuIsAdmin=ADMIN
	ConEmuPalette=<Solarized>
	ConEmuPID=3252
	ConEmuPrompt1=$P
	ConEmuPrompt2=$$
	ConEmuPrompt3=$S
	ConEmuServerPID=540
	ConEmuTask={Shells::cmd}
	ConEmuWorkDir=d:\code\node
	ConEmuWorkDrive=d:
	foobar=
	FSHARPINSTALLDIR=C:\Program Files (x86)\Microsoft SDKs\F#\4.1\Framework\v4.0\
	GOPATH=C:\bin\dev\go\work
	GOROOT=C:\bin\dev\go
	HOME=d:\refael
	HOMEDRIVE=d:
	HOMEPATH=\refael
	JAVA_HOME=C:\WINDOWS\System32\Java
	JDK_HOME=C:\WINDOWS\System32\Java
	LC_ALL=en_GB.UTF-8
	LOCALAPPDATA=d:\refael\AppData\Local
	LOGONSERVER=\\REFAELUX
	MSMPI_BIN=c:\Program Files\Microsoft MPI\Bin\
	NODE_PRESERVE_SYMLINKS=1
	NODE_REPL_MODE=strict
	NUMBER_OF_PROCESSORS=4
	OS=Windows_NT
	Path=C:\Tools\maint\conemu\ConEmu\Scripts;C:\Tools\maint\conemu;C:\Tools\maint\conemu\ConEmu;C:\Program Files\Docker\Docker\Resources\bin;c:\Program Files\Microsoft MPI\Bin\;C:\WINDOWS\system32\Tools;C:\WINDOWS\system32\downlevel;C:\WINDOWS\system32\Java\jre\bin;C:\WINDOWS\system32;C:\WINDOWS\system32\WindowsPowerShell\v1.0\;C:\WINDOWS\System32\Wbem;C:\WINDOWS;C:\bin\dev\node;C:\bin\dev\python27;C:\bin\dev\python27\Scripts;C:\bin\git\usr\bin;C:\bin\git\cmd;C:\Tools\maint;C:\Tools\dev;C:\code\tools;C:\code\tools\scripts;.\node_modules\.bin\;C:\Program Files\dotnet\;C:\Program Files (x86)\Windows Kits\8.1\Windows Performance Toolkit\
	PATHEXT=.JS;.;.CMD;.BAT;.EXE;.MSC;.COM
	PROCESSOR_ARCHITECTURE=AMD64
	PROCESSOR_IDENTIFIER=Intel64 Family 6 Model 58 Stepping 9, GenuineIntel
	PROCESSOR_LEVEL=6
	PROCESSOR_REVISION=3a09
	ProgramData=C:\ProgramData
	ProgramFiles=C:\Program Files
	ProgramFiles(x86)=C:\Program Files (x86)
	ProgramW6432=C:\Program Files
	PROMPT=@CLINK_PROMPT$P$$$S
	PSModulePath=C:\Program Files (x86)\WindowsPowerShell\Modules;C:\WINDOWS\system32\WindowsPowerShell\v1.0\Modules;C:\bin\dev\gcloud\google-cloud-sdk\platform\PowerShell;C:\Program Files (x86)\AWS Tools\PowerShell\
	PUBLIC=C:\Users\Public
	SEE_MASK_NOZONECHECKS=1
	SystemDrive=C:
	SystemRoot=C:\WINDOWS
	TEMP=c:\temp\usr
	TMP=c:\temp\usr
	USERDOMAIN=REFAELUX
	USERDOMAIN_ROAMINGPROFILE=REFAELUX
	USERNAME=refael
	USERPROFILE=d:\refael
	windir=C:\WINDOWS
	_NT_SYMBOL_PATH=srv*c:\bin\symbols*http://msdl.microsoft.com/download/symbols;srv*c:\bin\symbols*http://chromium-browser-symsrv.commondatastorage.googleapis.com

grandchild (cmd) 12272

High Resolution Date & Time:	02/08/2017 09:17:07.9592797
Event Class:	Process
Operation:	Process Start
Result:	SUCCESS
Path:	
TID:	13168
Duration:	0.0000000
Parent PID:	12272
Command line:	C:\WINDOWS\System32\cmd.exe /d /s /c "node -e console.log(process.env.foobar);"
Current directory:	d:\code\4node\
Environment:	
	ALLUSERSPROFILE=C:\ProgramData
	ANSICON=182x10000 (182x51)
	ANSICON_DEF=7
	APPDATA=d:\refael\AppData\Roaming
	CommonProgramFiles=C:\Program Files\Common Files
	CommonProgramFiles(x86)=C:\Program Files (x86)\Common Files
	CommonProgramW6432=C:\Program Files\Common Files
	COMPUTERNAME=REFAELUX
	ComSpec=C:\WINDOWS\System32\cmd.exe
	ConEmuANSI=ON
	ConEmuAnsiLog=undefined
	ConEmuArgs=/dir "d:\code\node"
	ConEmuArgs2=undefined
	ConEmuBackHWND=0x00060A5A
	ConEmuBaseDir=C:\Tools\maint\conemu\ConEmu
	ConEmuBuild=170517
	ConEmuConfig=undefined
	ConEmuDir=C:\Tools\maint\conemu
	ConEmuDrawHWND=0x00060A22
	ConEmuDrive=C:
	ConEmuHooks=Enabled
	ConEmuHWND=0x000606E4
	ConEmuIsAdmin=ADMIN
	ConEmuPalette=<Solarized>
	ConEmuPID=3252
	ConEmuPrompt1=$P
	ConEmuPrompt2=$$
	ConEmuPrompt3=$S
	ConEmuServerPID=540
	ConEmuTask={Shells::cmd}
	ConEmuWorkDir=d:\code\node
	ConEmuWorkDrive=d:
	foobar=undefined
	FSHARPINSTALLDIR=C:\Program Files (x86)\Microsoft SDKs\F#\4.1\Framework\v4.0\
	GOPATH=C:\bin\dev\go\work
	GOROOT=C:\bin\dev\go
	HOME=d:\refael
	HOMEDRIVE=d:
	HOMEPATH=\refael
	JAVA_HOME=C:\WINDOWS\System32\Java
	JDK_HOME=C:\WINDOWS\System32\Java
	LC_ALL=en_GB.UTF-8
	LOCALAPPDATA=d:\refael\AppData\Local
	LOGONSERVER=\\REFAELUX
	MSMPI_BIN=c:\Program Files\Microsoft MPI\Bin\
	NODE_PRESERVE_SYMLINKS=1
	NODE_REPL_MODE=strict
	NUMBER_OF_PROCESSORS=4
	OS=Windows_NT
	Path=C:\Tools\maint\conemu\ConEmu\Scripts;C:\Tools\maint\conemu;C:\Tools\maint\conemu\ConEmu;C:\Program Files\Docker\Docker\Resources\bin;c:\Program Files\Microsoft MPI\Bin\;C:\WINDOWS\system32\Tools;C:\WINDOWS\system32\downlevel;C:\WINDOWS\system32\Java\jre\bin;C:\WINDOWS\system32;C:\WINDOWS\system32\WindowsPowerShell\v1.0\;C:\WINDOWS\System32\Wbem;C:\WINDOWS;C:\bin\dev\node;C:\bin\dev\python27;C:\bin\dev\python27\Scripts;C:\bin\git\usr\bin;C:\bin\git\cmd;C:\Tools\maint;C:\Tools\dev;C:\code\tools;C:\code\tools\scripts;.\node_modules\.bin\;C:\Program Files\dotnet\;C:\Program Files (x86)\Windows Kits\8.1\Windows Performance Toolkit\
	PATHEXT=.JS;.;.CMD;.BAT;.EXE;.MSC;.COM
	PROCESSOR_ARCHITECTURE=AMD64
	PROCESSOR_IDENTIFIER=Intel64 Family 6 Model 58 Stepping 9, GenuineIntel
	PROCESSOR_LEVEL=6
	PROCESSOR_REVISION=3a09
	ProgramData=C:\ProgramData
	ProgramFiles=C:\Program Files
	ProgramFiles(x86)=C:\Program Files (x86)
	ProgramW6432=C:\Program Files
	PROMPT=@CLINK_PROMPT$P$$$S
	PSModulePath=C:\Program Files (x86)\WindowsPowerShell\Modules;C:\WINDOWS\system32\WindowsPowerShell\v1.0\Modules;C:\bin\dev\gcloud\google-cloud-sdk\platform\PowerShell;C:\Program Files (x86)\AWS Tools\PowerShell\
	PUBLIC=C:\Users\Public
	SEE_MASK_NOZONECHECKS=1
	SystemDrive=C:
	SystemRoot=C:\WINDOWS
	TEMP=c:\temp\usr
	TMP=c:\temp\usr
	USERDOMAIN=REFAELUX
	USERDOMAIN_ROAMINGPROFILE=REFAELUX
	USERNAME=refael
	USERPROFILE=d:\refael
	windir=C:\WINDOWS
	_NT_SYMBOL_PATH=srv*c:\bin\symbols*http://msdl.microsoft.com/download/symbols;srv*c:\bin\symbols*http://chromium-browser-symsrv.commondatastorage.googleapis.com

nicojs · 2017-08-02T13:27:01Z

@refack if it's not too much to ask, can you also confirm that you cannot reproduce it in Node v7.9? Just to make sure that it is indeed related to node 8 and up.

refack · 2017-08-02T13:45:59Z

@nicojs was just about to... but bad news:

d:\code\4node$ node790 -v             
v7.9.0                                
                                      
d:\code\4node$ node790 conemu-bug.js  
foobar was "undefined", using ConEmu? 
                                      
d:\code\4node$ node6 conemu-bug.js    
foobar was "undefined", using ConEmu? 
                                      
d:\code\4node$ node6 -v               
v6.11.1                               
                                      
d:\code\4node$ node4 conemu-bug.js    
foobar was "undefined", using ConEmu? 
                                      
d:\code\4node$ node4 -v               
v4.8.2

Seems like it's a ConEmu thing, but I'm dubugging

tniessen · 2017-08-02T13:46:22Z

Okay, I found the problem, this is caused by ConEmuHk.dll which is injected into all processes by default. (I had this feature disabled in my ConEmu setup so I was unable to reproduce the issue.)

By default, ConEmu injects its own DLL into all processes, including node:

nicojs · 2017-08-02T13:54:20Z

Wow! Disabled it and stuff works again like a charm!

Anyone running into this issue: setting can be found here:

So i guess an issue at ConEmu side after all (or in the injected dll). Tricky stuff. Thanks to all for your time! It took me several days to understand what was going wrong, but solving the issue only took a couple of hours. 💐

refack · 2017-08-02T14:37:56Z

I'm reopening since there is a node bug here:
An env variable with an undefined value gets converted into the string 'undefined'

evanlucas · 2017-08-02T14:39:31Z

@refack see #4920

cjihrig · 2017-08-02T14:40:12Z

This is documented behavior though.

refack · 2017-08-02T14:44:47Z

@refack see #4920

Ack, but that's just part of the story, here node is spawned in an environment with an undefined value...

nicojs · 2017-08-03T10:42:51Z

So how do we proceed? Apparently, node converts null to undefined, which it should not do? And only when the ConEmuHK.dll is injected into child processes an empty value is transformed to null? Is that the correct conclusion?

bnoordhuis · 2017-08-03T11:49:54Z

Node treats an empty string as an empty string. If it doesn't, that's a bug but I doubt that's the case here, or we would have received a small avalanche of bug reports by now.

I think a more likely explanation is that the parasitic code that ConEmu injects does something to GetEnvironmentVariableW() that breaks node. In fact, it seems like an inescapable conclusion because you mentioned that disabling injection of that DLL fixes the issue.

Maximus5 · 2017-08-04T16:51:36Z

Looks like it was changed in node 8.x because version 7.x doesn't suffer from the problem.

refack · 2017-08-04T17:12:11Z

I'll dig a bit.

bnoordhuis · 2017-08-09T14:32:11Z

@refack Any news?

refack · 2017-08-09T15:42:57Z

First @Maximus5 patched ConEmuHK.dll so it does not leak or swallow WIN32 errors anymore - Maximus5/ConEmu@5324aa0
I had a bit of trouble with #14641, but I think it's something I can manage once I get a free hour. That PR should close this issue.

payload · 2017-09-18T07:40:18Z

I am still affected by this bug in some CI setup without ConEmu. For the time being I downgraded nodejs to 6.11.1. Could we put the label confirmed-bug on this issue?

refack · 2017-09-18T11:33:08Z

@payload which version were you working with before?

payload · 2017-09-18T14:46:29Z

8.4.0

v9Chris · 2017-10-31T09:25:16Z

Experiencing this too, was driving me insane preventing me from building sqlite3 with node-gyp.

Win 10 / ConEmu / Node 8.8.0

After reading this thread I just tried it in cmd.exe and it worked first time.

nicojs · 2017-10-31T10:07:19Z

@v9Chris glad this issue could help you. I know the feeling 🤘

Maximus5 · 2017-10-31T10:41:43Z

That's why software updates are recommended.

hoodie · 2018-01-23T11:52:19Z

Any news whether node can be hardened against this without fixing the emulator? Sometimes these things are not under your control.

vweevers · 2018-01-29T00:35:35Z

Possibly related, without ConEmu:

var exec = require('child_process').exec

process.env.test = ''

if (process.argv[2] === 'trigger') {
  try { require('fs').readFileSync('foobar') } catch (e) {}
}

exec('node -p "process.env.test === \'undefined\' ? \'BUG\' : \'OK\'"', function (err, stdout) {
  if (err) throw err
  console.log(stdout)
})

Output:

> node test.js
OK
> node test.js trigger
BUG

But I can only trigger this on 4.8.7 x86 (also tried 9.2.0, 8.4.0, 8.0.0, 7.9.0, no problems there).

ajflash · 2018-02-11T19:41:48Z

Hello,

Maybe I have found something very similar related to the access of an undefined process.env variable in Windows. The env variable that does not exist in this test is "DUMMY_VAR".
The test code is extremely simple and I cannot give an explanation of the difference results I get with node v8.9.4:

process.env.applicationpath = "";
console.log("typeof process.env.applicationpath = " + typeof(process.env.applicationpath));

if (!process.env.DUMMY_VAR) {
// if (true) {
  console.log("  typeof process.env.applicationpath = " + typeof(process.env.applicationpath));
}

console.log("typeof process.env.applicationpath = " + typeof(process.env.applicationpath));

Output:

typeof process.env.applicationpath = string
  **typeof process.env.applicationpath = undefined**
typeof process.env.applicationpath = string

Which I think is wrong.
If I uncomment the "if true" line and I comment the if that access the undefined environment var the it works fine. The output now is:

typeof process.env.applicationpath = string
  **typeof process.env.applicationpath = string**
typeof process.env.applicationpath = string

I have tested the same code with node v5.5 and it gives the right expected result. In some way it seems that accessing the undefined environment variable is affecting the results in the other?

vweevers · 2018-02-12T13:51:47Z

In some way it seems that accessing the undefined environment variable is affecting the results in the other?

I suspect this is also why fs.readFileSync triggers the bug in my example. It's not the reading of an (unexisting) file that triggers it per se but that readFileSync does something with/to the environment.

BTW @payload I was unable to trigger it on v6.

richardlau · 2018-02-12T14:43:16Z

In some way it seems that accessing the undefined environment variable is affecting the results in the other?

@addaleax recently fixed #18463 which sounds like the example given by @ajflash.

addaleax · 2018-02-12T14:48:10Z

Yes, it’s exactly that bug.

/cc @nodejs/lts @gibfahn Just so you are aware, this seems to be a bug that quite a few people are running into and a (pretty much zero-risk) fix has been landed on master two weeks ago. It might be good to have this in 8.10.0, even if it doesn’t technically fulfill the lived-in-Current-for-2-weeks rule.

gibfahn · 2018-02-12T16:30:44Z

Sounds like a good candidate for expediting, will comment in #18463.

bzoz · 2018-02-14T12:17:58Z

Can this be closed now?

addaleax · 2018-02-18T14:59:46Z

@bzoz I think it might be easier to wait until this has been fixed in the v8.x branch, at least so we don’t forget about it

gibfahn · 2018-02-18T23:36:58Z

I've landed the fix in v8.x-staging, so I'll close.

mscdex added child_process Issues and PRs related to the child_process subsystem. v8.x labels Aug 2, 2017

nicojs closed this as completed Aug 2, 2017

nicojs mentioned this issue Aug 2, 2017

Passing empty environment variables to child processes convert to 'undefined' using ConEmu + Node Maximus5/ConEmu#1209

Open

refack reopened this Aug 2, 2017

refack mentioned this issue Aug 5, 2017

process: EnvGetter to use libuv #14641

Closed

3 tasks

hoodie mentioned this issue Sep 5, 2017

Cannot find module 'undefined' lerna/lerna#999

Closed

refack added confirmed-bug Issues with confirmed bugs. wip Issues and PRs that are still a work in progress. labels Sep 18, 2017

vweevers mentioned this issue Jan 28, 2018

adds appveyor config prebuild/prebuild#208

Merged

payload mentioned this issue Feb 2, 2018

test: add env undefined regression test #18529

Closed

gibfahn mentioned this issue Feb 12, 2018

process: fix reading zero-length env vars on win32 #18463

Closed

3 tasks

addaleax removed the wip Issues and PRs that are still a work in progress. label Feb 18, 2018

gibfahn closed this as completed Feb 18, 2018

addaleax mentioned this issue Feb 27, 2018

The value of process.env.foo can sometimes be observed to be undefined after being assigned the value of '' #19048

Closed

Passing empty environment variables to child processes convert to 'undefined' using ConEmu + Node #14593

Passing empty environment variables to child processes convert to 'undefined' using ConEmu + Node #14593

Comments

nicojs commented Aug 2, 2017

Problem description

Steps to reproduce

Actual results

Expected results

Screenshots:

ConEmu with cmd.exe shell

Command prompt with cmd.exe shell

bnoordhuis commented Aug 2, 2017

nicojs commented Aug 2, 2017 • edited Loading

bnoordhuis commented Aug 2, 2017

nicojs commented Aug 2, 2017 • edited Loading

bnoordhuis commented Aug 2, 2017

nicojs commented Aug 2, 2017

bnoordhuis commented Aug 2, 2017

nicojs commented Aug 2, 2017 • edited Loading

tniessen commented Aug 2, 2017

nicojs commented Aug 2, 2017 • edited Loading

bzoz commented Aug 2, 2017

bzoz commented Aug 2, 2017

nicojs commented Aug 2, 2017

refack commented Aug 2, 2017 • edited Loading

refack commented Aug 2, 2017

nicojs commented Aug 2, 2017

refack commented Aug 2, 2017

tniessen commented Aug 2, 2017

nicojs commented Aug 2, 2017

refack commented Aug 2, 2017

evanlucas commented Aug 2, 2017

cjihrig commented Aug 2, 2017

refack commented Aug 2, 2017

nicojs commented Aug 3, 2017 • edited Loading

bnoordhuis commented Aug 3, 2017

Maximus5 commented Aug 4, 2017 • edited Loading

refack commented Aug 4, 2017

bnoordhuis commented Aug 9, 2017

refack commented Aug 9, 2017 • edited Loading

payload commented Sep 18, 2017

refack commented Sep 18, 2017

payload commented Sep 18, 2017

v9Chris commented Oct 31, 2017

nicojs commented Oct 31, 2017

Maximus5 commented Oct 31, 2017

hoodie commented Jan 23, 2018

vweevers commented Jan 29, 2018

ajflash commented Feb 11, 2018 • edited by gibfahn Loading

vweevers commented Feb 12, 2018

richardlau commented Feb 12, 2018

addaleax commented Feb 12, 2018

gibfahn commented Feb 12, 2018

bzoz commented Feb 14, 2018

addaleax commented Feb 18, 2018

gibfahn commented Feb 18, 2018

nicojs commented Aug 2, 2017 •

edited

Loading

nicojs commented Aug 2, 2017 •

edited

Loading

nicojs commented Aug 2, 2017 •

edited

Loading

nicojs commented Aug 2, 2017 •

edited

Loading

refack commented Aug 2, 2017 •

edited

Loading

nicojs commented Aug 3, 2017 •

edited

Loading

Maximus5 commented Aug 4, 2017 •

edited

Loading

refack commented Aug 9, 2017 •

edited

Loading

ajflash commented Feb 11, 2018 •

edited by gibfahn

Loading