xargs: environment is too large for exec

[Martin Edwards]

Hi, I'm not sure if this is a mintty or cygwin thing.

When I try and run keychain I get the following message
xargs: environment is too large for exec

Running set to see what environment variables are set and I see thousands of lines, it looks like lots of functions that have been set.

Is this something to do with mintty or cygwin, I thought I had a fairly plain cygwin setup with mintty on top.

Any pointers or help appreciated.

[Chris Sutcliffe]

On 8 November 2011 14:28, Martin Edwards wrote:
> When I try and run keychain I get the following message
> xargs: environment is too large for exec
>
> Running set to see what environment variables are set and I see thousands of
> lines, it looks like lots of functions that have been set.

Cygwin inherits Windows environment variables. Is you run 'set' from
a Windows Command Prompt, do you see thousands of lines? If so,
that's where they are coming from.

Cheers,

Chris

--
Chris Sutcliffe
http://emergedesktop.org
http://www.google.com/profiles/ir0nh34d

[Kevin Calman]

Execute the following, and please post the result: "set | wc -c"
--
Opinions herein are exclusively my own, unless you share them.
Kevin Calman, codex24 at gmail dot com, Austin, TX, US

[Kevin Calman]

On Tue, Nov 8, 2011 at 3:34 PM, Kevin Calman <cod...@gmail.com> wrote:

On Tue, Nov 8, 2011 at 1:28 PM, Martin Edwards <martinm...@gmail.com> wrote:

Hi, I'm not sure if this is a mintty or cygwin thing.

When I try and run keychain I get the following message
xargs: environment is too large for exec

Running set to see what environment variables are set and I see thousands of lines, it looks like lots of functions that have been set.

Is this something to do with mintty or cygwin, I thought I had a fairly plain cygwin setup with mintty on top.

Any pointers or help appreciated.

Execute the following, and please post the result: "set | wc -c"

As suggested in https://www.gnu.org/software/findutils/manual/html_node/find_html/Error-Messages-From-xargs.html, you could try " xargs --show-limits" and see what it inspires. Here's what I get:

$ set | wc -c
301369
$ xargs --show-limits
Your environment variables take up 2772 bytes
POSIX upper limit on argument length (this system): 27180
POSIX smallest allowable upper limit on argument length (all systems): 4096
Maximum length of command we could actually use: 24408
Size of command buffer we are actually using: 27180

Execution of xargs will continue now, and it will try to read its input and run commands; if this is not what you wanted to happen, please type the end-of-file keystroke.
Warning: /bin/echo will be run at least once.  If you do not want that to happen, then press the interrupt keystroke.

$ keychain

KeyChain 2.6.8; http://www.gentoo.org/proj/en/keychain/
Copyright 2002-2004 Gentoo Foundation; Distributed under the GPL

 * Found existing ssh-agent (2748)

$

[Martin Edwards]

Here's the output as requested.

$ set | wc -c
254252

$ set | wc -l
7368

$ xargs --show-limits

xargs: environment is too large for exec

So all the lines I see when I just run set, are they environment
variables and functions set by windows?

Martin

On Nov 8, 9:34 pm, Kevin Calman <code...@gmail.com> wrote:

[Chris Sutcliffe]

On 9 November 2011 08:47, Martin Edwards wrote:
> So all the lines I see when I just run set, are they environment
> variables and functions set by windows?

Quite possibly. As I mentioned in an earlier email, start a Windows
Command Prompt (cmd.exe) and type 'set', if you see thousands of
environment variables, then it is Windows that is setting these and
Cygwin is inheriting them.

[Martin Edwards]

I've run 'set' in a Windows command prompt and there are only about 40
lines as opposed to the 7368 lines when I run it in a cygwin/bash
prompt under Mintty.

[Corinna Vinschen]

On Nov 9 05:47, Martin Edwards wrote:
> Here's the output as requested.
>
> $ set | wc -c
> 254252
>
> $ set | wc -l
> 7368
>
> $ xargs --show-limits
> xargs: environment is too large for exec
>
> So all the lines I see when I just run set, are they environment
> variables and functions set by windows?

"set" in bash prints all variables and functions, not only the
environment. That's what the "env" command is for.

This looks like a bug in xargs. Even if the environment is too
big, it should print the information requested by --show-limits.

There's also another problem here. Under POSIX, the sysconf(_SC_ARG_MAX)
or ARG_MAX limit is the limit of environmant and arguments combined.
That's why xargs --show-limits subtracts the environment size from the
maxiumum usable command length:

$ xargs --show-limits
Your environment variables take up 1986 bytes
POSIX upper limit on argument length (this system): 27966
[...]
Maximum length of command we could actually use: 25980

Neither is the upper limit correct, nor does subtracting the environment
size make sense on Cygwin. These values are independent from each other.

As for ARG_MAX/_SC_ARG_MAX, it's set to 32000. That'a safe fallback for
calling native Windows applications.

Corinna

[Kevin Calman]

On Wed, Nov 9, 2011 at 9:21 AM, Corinna Vinschen <google...@vinschen.de> wrote:

This looks like a bug in xargs.  Even if the environment is too
big, it should print the information requested by --show-limits.

Even still, the results I got showed my environment is larger than Martin's and mine works, so there must be something else at work.

Martin, try this snippet:

$ env | awk -F= '{I=$1;sub(/_.*$/,"",I);C[I]++};END{for (J in C) if (C[J] > 1) printf "%d\t%s\n", C[J], J}' | sort -nk1
2       M2
2       SSH
2       windows
3       JAVA
5       PROCESSOR
5       TEXDOCVIEW

The command produces a table of counts of environment entry names truncated at the first '_' character. This will give you an idea of where large numbers of environment entries are coming from. For example, the last result above is due to my environment containing:

$ env | grep \^TEXDOCVIEW
TEXDOCVIEW_dvi='cygstart %s'
TEXDOCVIEW_html='cygstart %s'
TEXDOCVIEW_pdf='cygstart %s'
TEXDOCVIEW_ps='cygstart %s'
TEXDOCVIEW_txt='cygstart %s'

You could then remove these environment definitions (from the current session only) with something like,

for I in $(env | grep \^TEXDOCVIEW | cut -d= -f1); do unset $I; done

Try doing this to reduce your environment size until xargs works.

[Andy Koppe]

On Nov 9, 1:47 pm, Martin Edwards wrote:
> Here's the output as requested.
>
> $ set | wc -c
> 254252
>
> $ set | wc -l
> 7368
>
> $ xargs --show-limits
> xargs: environment is too large for exec
>
> So all the lines I see when I just run set, are they environment
> variables and functions set by windows?

I wouldn't be surprised at all if they were set by the ever-
troublesome bash-completion package. Try uninstalling that through
setup.exe or disabling it by renaming /etc/profile.d/
bash_completion.sh to something not ending in .sh. (Tab completion for
all the usual stuff such as commands and filenames will still work;
the bash-completion package adds completion for other command
arguments such as options or repository paths.)

In any case, the Cygwin mailing list would be a better place for this
thread.

Andy