That's useful when trying to rely on files only present in source and/or
build directories, not in the normal installation. E.g. the
isolationtester binary, or the valgrind suppression files.
If postgres was compiled without flex support - possible when building
from a tarball, because those contain the flex generated files - citus
compilation would fail, because FLEX is defined as missing.
Add detection for flex, overwriting postgres' detection if one was
found.
Fixes: #439
I came across several places we weren't as flexible or resilient as we
should have been in our build logic. They include:
* Not using `DESTDIR` in the install-header destination
* Allowing callers to specify `VPATH` or `srcdir` (which breaks)
* Using absolute path for SCRIPTS (9.5 prepends srcdir)
* Including libpq-int in a confusing way (extracted this function)
* Having server includes come first during csql build (client must)
In particular, I hit all of these attempting to build with pg_buildext
in Debian. It passes in an explicit VPATH, as well as srcdir (breaking
all recursive make invocations), and also uses DESTDIR during install.
In addition, a PGDG-enabled Debian box will have the latest libpq-dev
headers (e.g. 9.5) even when building against an older server version
(e.g. 9.4). This leads to problems when including e.g. `c.h`, which
is ambiguous. While compiling more client-side code (csql), we need to
ensure the newer libpq headers are included _first_, so I fixed that.
All citusdb references in
- extension, binary names
- file headers
- all configuration name prefixes
- error/warning messages
- some functions names
- regression tests
are changed to be citus.