CHANGELOG

This file lists breaking changes and major features (not each individual bug fix)

## 0.9.x:

 - Drop support for python 2

## 0.8.x:

 - Overhaul of path and symlink code to iron out a number of edge case bugs,
   particularly in cases where `abspath(normpath(p)) != abspath(p)`.

 - Changed `cwd` for indirect (Gupfile) build scripts. Now all buildscripts
   are executed from the location of the `Gupfile` (without the `gup/`
   component), not the buildscript. The description in the README was ambiguous
   as to how this worked, so I chose to resolve this in favour of the approach that
   is easier to both implement and explain.

## 0.7.x:

 - Warn (instead of failing) when actions like `--always` are used outside of a target

 - Support `!exe` in Gupfile, to use `exe` from `$PATH`

 - Add `gup-git-tree-builder`

## 0.6.x:

 - Add `--keep-failed` flag

 - Warn when removing stale target

 - Add `--leave` and `--dirty`

 - Move suffix -> prefix (see #11 for rationale)

## 0.5.x:

Improvements dealing with symbolic links

## 0.4.x:

 - Breaking change: delete "$2" if it hasn't been `touched`, even if it's a
directory.

 - treat `#!/path/to/env foo` as `#!foo` if `/path/to/env` doesn't exist.

## 0.3.x:

- Replaced default jobserver implementation (anonymous pipe) with a named pipe,
whose path is passed to children in $GUP_JOBSERVER.

The previous make-compatible implementation has issues with many modern languages,
which automatically close all open file descriptors on `exec` that the programmer
doesn't explicitly declare as being shared. This is enforced in nodejs and go,
and is likely to become the default behaviour in a future version of python.

`gup` will still use a make-supplied jobserver if it's present (in $MAKEFLAGS),
but you'll have to invoke `gup` from `make` for that to be the case.

- Uncovered, added tests for and fixed a number of issues in gup's jobserver
implementation:

	- toplevel `gup` instance doesn't wait for children to finish if one fails

	- ocaml implementation used an unbounded number of concurrent jobs, regardless
	of what --jobs` is set to

	- ocaml implementation fell afoul of `flock()`s insane behaviour: builds
	lose their WriteLock before they even call the build script because to a
	ReadLock on an unrelated file descriptor (for the same inode) is released.
	This caused invalid (partially truncated) .deps files to be written in many
	parallel builds.