These can be used to determine whether a ELF file with ELF header is an
executable or shared library.
We can't implement it in pure bash, as bash has problems with null
bytes.
That's very much consistent with the spirit of nix-shell --pure
BTW, nix 1.x shells will be always treated as pure;
in that version detection isn't possible.
https://github.com/NixOS/nix/commit/1bffd83e1a9c
Some SSL libs don't react to $SSL_CERT_FILE.
That actually makes sense to me, as we add this behavior
as nixpkgs-specific, so it seems "safer" to use $NIX_*.
We want initialPath to have lowest precedence.
In addition, unset _PATH and _HOST_PATH as they shouldn’t be needed
after final PATH and HOST_PATH are set.
Completely breaks darwin. Every package in the stdenv that has shebangs
in the output will end up with references to bootstrap-tools.
This reverts commit eb7c50a993.
In strictDeps=false, autoPatchshebangs should use
--build (corresponding to PATH) to lookup commands. This restores the
previous behavior of patchshebangs so that we don’t break stuff that
isn’t careful in the buildInputs vs. nativeBuildInputs distinction.
Unfortunately this won’t work under cross compilation.
The isELF function only checks whether ELF is contained within the first
4 bytes of the file, which is a bit fuzzy and will also return
successful if it's a text file starting with ELF, for example:
ELF headers
-----------
Some text here about ELF headers...
So instead, we're now doing a precise match on \x7fELF.
Signed-off-by: aszlig <aszlig@nix.build>
Acked-by: @Ericson2314
Closes: https://github.com/NixOS/nixpkgs/pull/47244
a4630c65ca was incorrect in assuming $SHELL would be a path to the
bash derivation. In fact $SHELL will be a path to the bash executable.
Unfortunately this did not fix the original issue. So instead, we just
have to reuse initialPath can be added like PATH is.
Sorry for the inconvenience! I hadn’t thought through the effects of
the last commit.
/cc @copumpkin @ericson2314
To avoid breaking things, we need to make sure SHELL goes into
HOST_PATH. This reflects my changes to patch-shebangs to make it cross
compilation ready. When a script is patched from the Nix store it now
looks to HOST_PATH to get the targeted machine’s executables.
Unfortunately, this only works in native builds.
Works similarly to `enableParallelBuilding`, but is set by default when
`enableParallelBuilding` is set. In my experience most packages that build
fine in parallel also check fine in parallel.
HOST_PATH contains the path of the host package. This will include the
packages listed in buildInputs & depsHostHost. Use this to find
runtime commands that the host needs.
For instance to find the runtime version of perl,
$ PATH="$HOST_PATH" command -v perl
/nix/store/...-perl-5.28.0-aarch64-unknown-linux-android/bin/perl
This path should not be executed directly (it will break for cross
compilation). Only use it to find the location of executables that
will be run by your host system. Your build tools will, as always, be
available on the default PATH.
The line was essentially checking whether /bin/sh exists and is
executable and if that's the case, the isScript function returns
successfully.
When asking the author of this line on IRC it seems that even they can't
remember or imagine what this was supposed to be.
In summary: Whenever /bin/sh doesn't exist during a build, *any* file
given to isScript is reported as being a script even if it isn't.
This is kinda counter-intuitive and not something what somebody would
expect from a function called "isScript".
Signed-off-by: aszlig <aszlig@nix.build>
Cc: @edolstra
The hack of using `crossConfig` to enforce stricter handling of
dependencies is replaced with a dedicated `strictDeps` for that purpose.
(Experience has shown that my punning was a terrible idea that made more
difficult and embarrising to teach teach.)
Now that is is clear, a few packages now use `strictDeps`, to fix
various bugs:
- bintools-wrapper and cc-wrapper
- All deps go on the PATH
- CC and Bintools wrappers with their host != depender's host still get their
setup hooks run.
- Environment hooks get applied to all packages
This isn't so elegent, but eases the transition on a very significant
PR.
We now have the information to properly determine the role the
cc-wrapper dependency has, by taking advantage of `offset`. No longer
use the soon-to-be-deprecated crossConfig environment variable, the
temp hack used before this change.
4 far-reaching changes: Smaller PATH, New vars, different propagation
logic, and different hook logic
Smaller PATH
------------
`buildInputs` no longer go on the PATH at build time, as they cannot be
run when cross compiling and we don't want to special case. Simply make
a `nativeBuildInput` too if one needs them on the PATH. Fixes#21191.
Many new depedendency variables
-------------------------------
See the stdenv chapter of the nixpkgs manual. I pulled out the existing
documentation of dependency specification into a new section, and added
language for these two (and their propagated equivalents) along side
the others'.
More complex propagation logic
------------------------------
Before a propagated*XXX*Input always acted as if it was specified
directly as a *XXX*Input downstream. That's simple enough, but violates
the intended roles of each sort of dep, which has functional and not
just stylistic consequences.
The new algorithm is detailed in the manual, and ensures everything
ends up in the right place. I tried to give both an informal and formal
description, but I suspect in practice it will not make much sense
until one tries cross compiling, after which it will immediately make
sense as the only sane option.
Simplified hook logic
---------------------
Rather than `envHook` and `crossEnvHook`, whose behavior differs
depending on whether we are cross compiling or not, there is now one
hook per sort (or rather non-propagated and propagated pair of sorts)
of dependency. These new hooks have the same meaning regardless of
cross compilation. See the setup hook section of stdenv chapter of the
Nixpkgs manual for more details.
This continues #23374, which always kept around both attributes, by
always including both propagated files: `propgated-native-build-inputs`
and `propagated-build-inputs`. `nativePkgs` and `crossPkgs` are still
defined as before, however, so this change should only barely
observable.
This is an incremental step to fully keeping the dependencies separate
in all cases.
I find the separation of concerns, accumulating, then processing, easier
to follow. Also, with my yet-to-be-merged cross work, the accumulation
part will become more complex.
Why 6? It seems a decently high number, giving us room for more degrees
of debugging before the `set -x` sledgehammer without incurring a
mass-rebuild.
Environment variable filter in substituteAll was not precise and produced
undefined and invalid variable names. Vladimír Čunát tried to fix that in [1],
but `env -0` did not work during Darwin bootstrap, so [2] reverted this change
and replaced an error due to invalid variables with a warning. Recently in #28057
John Ericson added `set -u` to `setup.sh` and undefined variables made the setup
fail during e.g. `nix-build -A gnat` with `setup: line 519: !varName: unbound
variable`.
[1] 62fc8859c1
[2] 81df035429
Older bash version, like those in the bootstrap tools and on macOS,
currently confuse variables defined as an empty array with undefined
variables. `${foo+"${foo[@]}"}` will prevent `set -u` problems with
empty arrays and older without making a single '' in the empty case.
Care is taken to `set +u` when running hooks so as to not break existing
packages.
This reverts commit eeabf85780.
This change suddenly makes tons of stdenv internals visible in
nativeBuildInputs of every derivation, which doesn't seem desirable.
E.g:
````
nix-repl> hello.nativeBuildInputs
[ «derivation /nix/store/bcfkyf6bhssxd2vzwgzmsbn7b5b9rpxc-patchelf-0.9.drv»
«derivation /nix/store/4wnshnz9wwanpfzcrdd76rri7pyqn9sk-paxctl-0.9.drv»
<< snip 10+ lines >>
«derivation /nix/store/d35pgh1lcg5nm0x28d899pxj30b8c9b2-gcc-wrapper-6.4.0.drv»
]
````
Additionally, instead of pulling them from `setup.sh`, route them via
Nix. This gets us one step closer to making stdenv be a plain attribute
set instead of a derivation.
