This value is require to get c++ std include path for libclang based tools (vim plugins in my case).
I currently extract it this with this rather command:
```
eval echo $(nix-instantiate --eval --expr 'with (import <nixpkgs>) {}; clang.default_cxx_stdlib_compile')
```
it did not trigger any recompilation on my system.
`SSL_CERT_FILE` has been replaced with `NIX_SSL_CERT_FILE`.
Before this change using `fetchdarcs` resulted in an error message like:
```
Identifying repository http://hub.darcs.net/scravy/easyplot inventory
darcs failed: Not a repository: http://hub.darcs.net/scravy/easyplot (Peer certificate cannot be authenticated with given CA certificates)
HINT: Do you have the right URI for the repository?
builder for ‘/nix/store/imyvcs6lvb5yva66krc5wk39931sam8v-fetchdarcs.drv’ failed with exit code 2
```
I was getting the following error building tide from Melpa:
nix-build -E '(import <nixpkgs> {}).emacs25WithPackages (p: [p.melpaPackages.tide])'
File tide-20170509.1134.tar is large (10.2M), really open? (y or n) Error reading from stdin
builder for ‘/nix/store/gs9ik7yf8iilsikkfing74i70m0diax3-emacs-tide-20170509.1134.drv’ failed with exit code 255
cannot build derivation ‘/nix/store/m3p080aani4rw82llp8nqk93cw2nvirk-emacs-with-packages-25.2.drv’: 1 dependencies couldn't be built
Solution was to disable the large file warning threshold when
installing packages.
This still causes some uncached rebuilds, but master(!) and staging
move too fast forward rebuild-wise, so Hydra might never catch up.
(There are also other occasional problems.)
Therefore I merge at this point where the rebuild isn't that bad.
We need to make sure that `$revs` ends with a space, since files must always
end with newlines. The previous code ignored the last entry in `$revs`, because
read already returns non-zero exit code for the last entry, as it does not end
with a space.
This change fixes several defects in the way `wrapGAppsHook` selected
the executable to wrap.
Previously, it would wrap any top-level files in the target `/bin` and
`/libexec` directories, including directories and non-executable
files. In addition, it failed to wrap files in subdirectories.
Now, it uses `find` to iterate over these directory hierarchies,
selecting only executable files for wrapping.
This change fixes several defects in the way `wrapGAppsHook` selected
the executable to wrap.
Previously, it would wrap any top-level files in the target `/bin` and
`/libexec` directories, including directories and non-executable
files. In addition, it failed to wrap files in subdirectories.
Now, it uses `find` to iterate over these directory hierarchies,
selecting only executable files for wrapping.
When not using sandboxing, /usr/share/git-core/templates may leak into the
nix build through the libgit2 hardcoded default template search path. We now
explictly set the templatedir to avoid this problem.
See https://github.com/bennofs/nix-index/issues/2#issuecomment-296268983 for
an example case of nondeterminism.
This typo was likely introduced by copy-pasting the error message from elsewhere and forgetting to change the text, during the MD5 deprecation process (#4491).
This patch fixes file modification times to $SOURCE_DATE_EPOCH, and
ensures that files originating from the store are owned by root:root.
Both changes improve reproducibility, and the latter allows proper
building on a host where the store is owned by a non-root user.
