It seems to me that with Ubuntu Precise Pangolin it is all but easy to do a proper install of SANE from source (git-repo).

I've found other scanning issues trying to find an answer to this, where the output people posted seems to indicate they suffer the same issue (unknowingly).

If I run on a fresh install of Ubuntu 12.04 with compiled SANE source from the git I get:

$ scanimage -V
scanimage (sane-backends) 1.0.24git; backend version 1.0.22

(I basically followed the instructions on http://ubuntuportal.com/2012/02/how-to-get-an-canon-canoscan-lide-100-scanner-to-work-in-ubuntu-11-10linux-mint-12.html since I didn't find any other information making sure that sane was not installed prior to installation.)

My primary interest is the epson2-backend. In 1.0.22 it offers the wrong TPU settings for Epson V700 (TPU2-mode wasn't supported in 1.0.22, and the scanner is useless to me if I don't have the TPU2-support).

Since if I ask it to enter transparency mode, it shows 1.0.22 behaviour, it implies that the epson2-backend comes from 1.0.22 and not 1.0.24 even though I just built it.

If I install SANE with prefix to a local folder and run that version of scanimage it still produces the mismatch.

However, on another computer where I installed a custom 1.0.22 build of SANE prior to upgrading to Ubuntu 12.04, I can build and install the same SANE-git locally and have it correctly match backends:

$ ./SANE/bin/scanimage -V
scanimage (sane-backends) 1.0.24git; backend version 1.0.24
$ scanimage -V
scanimage (sane-backends) 1.0.22; backend version 1.0.22

On this computer the 1.0.24 works correctly in finding TPU2 on Epson V700.

So what am I missing/doing wrong?

(And I want to replace 1.0.22 with 1.0.24 for the whole system, the local build was just debugging.)

Any help would be much appreciated.

Edit 1:

Just tried compiling SANE using this instruction on Ubuntu 10.04 and it worked like a charm. However, when I upgraded to 12.04 (really would like to run 12.04), SANE was downgraded to 1.0.22. When trying the same set of instructions on 12.04 I was still out of luck -- the backend missmatch was there again (and I do have libusb-dev installed)

Edit 2:

I updated to Ubuntu 12.10 which now has the 1.0.23 SANE drivers. I haven't dared trying to compile from source on 12.10 since 1.0.23 is good enough for me. This is just a work-around and I would still like to know what's up with Ubuntu 12.04.