Berkeley DB cannot be found on Ubuntu

[daniel s. <dan...@gm...>]

Hi,

While building mbsync from the git repo, I see:

Using SSL
Using SASL
Using zlib
Not using Berkeley DB

This doesn't make sense to me as Berkeley DB is installed as far as I'm
concerned.
The config.log reveals:

configure:4723: checking for Berkeley DB >= 4.1
configure:4745: gcc -o conftest -g -O2 -pipe -W -Wall -Wshadow
-Wstrict-prototypes -ansi -pedantic -Wno-overlength-strings  -D_GNU_SOURCE
     -ldb conftest.c  >&5
conftest.c:34:1: warning: function declaration isn't a prototype
[-Wstrict-prototypes]
 main ()
 ^
/tmp/ccaGDsAw.o: In function `main':
/home/daniel/isync-isync/conftest.c:37: undefined reference to `db_create'
collect2: error: ld returned 1 exit status

So the linker cannot find the required function. Interesting.

If I had to guess, which I really shouldn't because I'm not a C programmer
at all, the problem is that recent versions of gcc require that you put the
object files and libraries in the order that they depend on each other. In
other words, conftest.c should be before -ldb. This is actually consistent
from what I observe elsewhere in the log, for example conftest.c precedes
-lsasl2, etc.

I'm curious to learn more about this.