<p>After poking around a bit, I see that I can set this in Bash before running fv:</p>
<p><code>export POW_HELPDIR=/usr/share/doc/ftools-pow</code></p>
<p>which fixes it and lets me browse the help documentation.</p>
<p><em>Update</em>: the FTOOLS Help Desk reports that this is apparently a packaging issue in Ubuntu, and is not a problem for the <a href="https://heasarc.gsfc.nasa.gov/lheasoft/ftools/fv/fv_download.html" rel="nofollow noreferrer">versions they distribute directly</a>.</p>
<p><em>Update 2</em>: I just reported this bug to the packagers: <a href="https://bugs.launchpad.net/ubuntu/+source/ftools-fv/+bug/1982671" rel="nofollow noreferrer">https://bugs.launchpad.net/ubuntu/+source/ftools-fv/+bug/1982671</a></p>

CC BY-SA 4.0
2022-07-21T18:40:21.247Z
2022-07-23T19:25:53.483Z
2022-07-23T19:25:53.483Z
nealmcb
<p>I'm launching the <code>pow</code> tool from <code>fv</code> version 5.5, installed via apt on Ubuntu 20.04.
It is part of <a href="https://heasarc.gsfc.nasa.gov/docs/software.html" rel="nofollow noreferrer">HEASoft's FITS software suite</a>.</p>
<p>I click on the menu Help/About and I get this error message:</p>
<pre><code>Error: can't read &quot;env(POW_HELPDIR)&quot;: no such variable
</code></pre>
<p>How can I get to the help files?</p>

<fits>
Can't read documentation in pow, launched form fv: Error: can't read "env(POW_HELPDIR)": no such variable
nealmcb
# Can't read documentation in pow, launched form fv: Error: can't read "env(POW_HELPDIR)": no such variable

(Asked by: username_0 on 2022-07-21)

I'm launching the pow tool from fv version 5.5, installed via apt on Ubuntu 20.04.
It is part of HEASoft's FITS software suite.
I click on the menu Help/About and I get this error message:
Error: can't read "env(POW_HELPDIR)": no such variable

How can I get to the help files?

**Tags:** fits

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## 1 answers

### Answer by username_0 on 2022-07-21. Score: 3 | Accepted answer

After poking around a bit, I see that I can set this in Bash before running fv:

`export POW_HELPDIR=/usr/share/doc/ftools-pow`

which fixes it and lets me browse the help documentation.

*Update*: the FTOOLS Help Desk reports that this is apparently a packaging issue in Ubuntu, and is not a problem for the [versions they distribute directly](https://heasarc.gsfc.nasa.gov/lheasoft/ftools/fv/fv_download.html).

*Update 2*: I just reported this bug to the packagers: <https://bugs.launchpad.net/ubuntu/+source/ftools-fv/+bug/1982671>


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