doc/manual/source/release-notes/rl-2.3.md
This is primarily a bug fix release. However, it makes some incompatible changes:
It also has the following changes:
builtins.fetchGit's ref argument now allows specifying an
absolute remote ref. Nix will automatically prefix ref with
refs/heads only if ref doesn't already begin with refs/.
The installer now enables sandboxing by default on Linux when the system has the necessary kernel support.
The max-jobs setting now defaults to 1.
New builtin functions: builtins.isPath, builtins.hashFile.
The nix command has a new --print-build-logs (-L) flag to
print build log output to stderr, rather than showing the last log
line in the progress bar. To distinguish between concurrent builds,
log lines are prefixed by the name of the package.
Builds are now executed in a pseudo-terminal, and the TERM
environment variable is set to xterm-256color. This allows many
programs (e.g. gcc, clang, cmake) to print colorized log
output.
Add --no-net convenience flag. This flag disables substituters;
sets the tarball-ttl setting to infinity (ensuring that any
previously downloaded files are considered current); and disables
retrying downloads and sets the connection timeout to the minimum.
This flag is enabled automatically if there are no configured
non-loopback network interfaces.
Add a post-build-hook setting to run a program after a build has
succeeded.
Add a trace-function-calls setting to log the duration of Nix
function calls to stderr.