document how to set tmpdir

• Pip version: 9.0.1
• Python version: 3.5.3
• Operating system: Linux

Description:

My /tmp directory is on a partition without enough space to build a (big) package. From the documentation (and unfamiliarity with pip) I expected that specifying --build to another directory would move all of pip’s temporary building activity to that directory:

pip3 install --build /lots/of/space thepackage

Of course, it did not.

Eventually I found out that setting TMPDIR to the desired directory would do it (in bash).

I recommend providing an option to specify the tmpdir, or (maybe better) saying something in the documentation about how to do this. Perhaps, by adding to the documentation for --build something like perhaps: “The initial build will still take place in an OS-specified temporary directory (change this by setting TMPDIR).”

[pradyunsg]

Indeed.

As I understand, a documentation-only fix for this would be to add note to the documentation of --build that the TMPDIR environment variable has to be used to change the location of temporary builds that pip does.

[pradyunsg]

Hi @1byxero! Go ahead. @xavfernandez wrote a summary above.

Ping me by mentioning me on this issue if you need help. 😃