Merge branch 'stopgap-simd-io-2.6' into 'releases/2.6'

ref:core/dune-common Addresses: [dune-istl#60]

See merge request [!593]

  [dune-istl#60]: gitlab.dune-project.org/Nonedune-istl/issues/60
  [!593]: gitlab.dune-project.org/core/dune-common/merge_requests/593

Addresses: dune-istl#60

Merge branch 'fix-vc-index-types-2.6' into 'releases/2.6'

ref:core/dune-common These are also used by the new simd interface on master
and appear to be more portable between different Vc vector and simdarray
implementations.

For the mask type, this seems to be unnecessary.

Closes: [dune-istl#59]

See merge request [!592]

  [dune-istl#59]: gitlab.dune-project.org/Nonedune-istl/issues/59
  [!592]: gitlab.dune-project.org/core/dune-common/merge_requests/592

These are also used by the new simd interface on master and appear to be more
portable between different Vc vector and simdarray implementations.

For the mask type, this seems to be unnecessary.

Merge branch 'debugalign-overload-min-max-2.6' into 'releases/2.6'

ref:core/dune-common A superficial reading of the standard's
LessThanComparable requirement may suggest that we could actually use
std::min() and std::max(). But as it turns out this isn't all that clear, see
[https://cplusplus.github.io/LWG/issue2114]. libc++ chose LessThanComparable
in a way that requires the result of the comparison to be implicitly
convertible to bool, which we cannot guarantee as we do not want the debug
type the automatically decay into its underlying type in all kinds of
contexts. So we go with the alternative route of overloading min() and max().

Cherry-picks [!550] onto releases/2.6

Closes: [dune-istl#57]

See merge request [!590]

  [https://cplusplus.github.io/LWG/issue2114]: https://cplusplus.github.io/LWG/issue2114
  [!550]: gitlab.dune-project.org/NoneNone/merge_requests/550
  [dune-istl#57]: gitlab.dune-project.org/core/dune-istl/issues/57
  [!590]: gitlab.dune-project.org/core/dune-common/merge_requests/590

A superficial reading of the standard's LessThanComparable requirement may
suggest that we could actually use std::min() and std::max().  But as it turns
out this isn't all that clear, see https://cplusplus.github.io/LWG/issue2114.
libc++ chose LessThanComparable in a way that requires the result of the
comparison to be implicitly convertible to bool, which we cannot guarantee
as we do not want the debug type the automatically decay into its underlying
type in all kinds of contexts.  So we go with the alternative route of
overloading min() and max().

Cherry-picks !550 onto releases/2.6

Closes: dune-istl#57

Merge branch 'ci/centralize-config-2.6' into 'releases/2.6'

See merge request [!587]

  [!587]: Nonecore/dune-common/merge_requests/587

Merge branch 'backport/cmake-labels' into 'releases/2.6'

ref:core/dune-common @timo.koch has a dire need for this on the release branch
and I do not see why we shouldnt allow it.

See merge request [!575]

  [!575]: gitlab.dune-project.org/core/dune-common/merge_requests/575

Merge branch 'cherry-pick-5b3ea34f' into 'releases/2.6'

ref:core/dune-common \[bugfix\] VariableSizeCommunicator fixes

See merge request [!520]

(cherry picked from commit 5b3ea34f)

66c0332a Removed bogus assert to allow interface with no elements. 83e9e8d3
Initialize requests with MPI_REQUEST_NULL to ignore invalid ones when waiting.
30e78443 Determine number of requests by checking how many or not
MPI_REQUEST_NULL.

See merge request [!522]

  [!520]: gitlab.dune-project.org/core/dune-common/merge_requests/520
  [!522]: gitlab.dune-project.org/core/dune-common/merge_requests/522

[dune_add_test()] Allow to attach labels to tests.

See merge request !423
(cherry picked from commit 1735b5b7)

Merge branch 'cherry-pick-709ea8aa' into 'releases/2.6'

ref:core/dune-common Merge branch 'bugfix/add_to_unique_ptr_to_CmakeLists'
into 'master'

Header was missing in CMakeLists.txt and now breaks code due to usage in
dune-grid Needs to be backported to 2.6

See merge request [[!547]]

(cherry picked from commit 709ea8aa)

53f306b7 added missing header to_unique_ptr.hh to CMakeLists.txt

See merge request [!549]

  [!547]: gitlab.dune-project.org/core/dune-common/merge_requests/547
  [!549]: gitlab.dune-project.org/core/dune-common/merge_requests/549

Merge branch 'cherry-pick-1e7fbb59-3' into 'releases/2.6'

ref:core/dune-common Merge branch 'let-cmake-disable-pkgconfig-search' into
'master'

For whatever reason we still allow to search for a module with pkg-config if
CMake was not successful. This leads to the weired situation that if we pass
-DCMAKE_DISABLE_FIND_PACKAGE_dune-uggrid=ON to cmake and dune-uggrid is
installed in a default sytem path we will end up with a CMakeCache.txt
actually using dune-uggrid.

This patch is the minimal change to stop searching for a DUNE module with
pkg-config if CMake was instructed not to use it.

See merge request [[!569]]

(cherry picked from commit 1e7fbb59)

df4c73f6 Let cmake disable search for modules with pkg-config.

See merge request [!571]

  [!569]: gitlab.dune-project.org/core/dune-common/merge_requests/569
  [!571]: gitlab.dune-project.org/core/dune-common/merge_requests/571

Merge branch 'cherry-pick-43772da6' into 'releases/2.6'

ref:core/dune-common Merge branch 'feature/range-with-enums' into 'master'

Fixes the defect of the single argument range(\...) that enum values could not
be used without casting. I would like to see this being backported to 2.6.

See merge request [[!553]]

(cherry picked from commit 43772da6)

48c8702f \[bugfix\] allow single argument range(...) with enum values

See merge request [!555]

  [!553]: gitlab.dune-project.org/core/dune-common/merge_requests/553
  [!555]: gitlab.dune-project.org/core/dune-common/merge_requests/555

Merge branch 'backport/dense-vector-assignment' into 'releases/2.6'

ref:core/dune-common Please.

See merge request [!563]

  [!563]: gitlab.dune-project.org/core/dune-common/merge_requests/563

Merge branch 'cherry-pick-b7c41305' into 'releases/2.6'

ref:core/dune-common [cmake][dune_add_test] Fix/dune add test cmake guard skip
test

See merge request [!409] (cherry picked from commit
b7c41305)

See merge request [!558]

  [!409]: gitlab.dune-project.org/core/dune-common/merge_requests/409
  [!558]: gitlab.dune-project.org/core/dune-common/merge_requests/558

Merge branch 'cherry-pick-27af4005' into 'releases/2.6'

ref:core/dune-common [cmake][dune_add_test] Set test property to depend on
existence of target

Closes [#100]

See merge request [!404]

(cherry picked from commit 27af4005)

69efd0be [cmake][dune_add_test] Set test property to depend on existence of
target

See merge request [!557]

  [#100]: gitlab.dune-project.org/NoneNone/issues/100
  [!404]: gitlab.dune-project.org/core/dune-common/merge_requests/404
  [!557]: gitlab.dune-project.org/core/dune-common/merge_requests/557

Merge branch 'let-cmake-disable-pkgconfig-search' into 'master'

For whatever reason we still allow to search for a module with pkg-config if
CMake was not successful. This leads to the weired situation that if we pass
-DCMAKE_DISABLE_FIND_PACKAGE_dune-uggrid=ON to cmake and dune-uggrid is
installed in a default sytem path we will end up with a CMakeCache.txt
actually using dune-uggrid.

This patch is the minimal change to stop searching for a DUNE module with
pkg-config if CMake was instructed not to use it.

See merge request [!569]

  [!569]: gitlab.dune-project.org/core/dune-common/merge_requests/569


(cherry picked from commit 1e7fbb59)

df4c73f6 Let cmake disable search for modules with pkg-config.

[cmake][dune_add_test] Fix/dune add test cmake guard skip test

See merge request !409
(cherry picked from commit b7c41305)

[cmake][dune_add_test] Set test property to depend on existence of target

Closes #100

See merge request !404

(cherry picked from commit 27af4005)

69efd0be [cmake][dune_add_test] Set test property to depend on existence of target

Merge branch 'cherry-pick-317d5564-2' into 'releases/2.6'

fixed typo in variable

See merge request [!456]

(cherry picked from commit 317d5564)

444bac38 fixed typo in variable

See merge request [!556]

  [!456]: gitlab.dune-project.org/core/dune-common/merge_requests/456
  [!556]: gitlab.dune-project.org/core/dune-common/merge_requests/556

fixed typo in variable

See merge request !456

(cherry picked from commit 317d5564)

444bac38 fixed typo in variable

Merge branch 'feature/range-with-enums' into 'master'

Fixes the defect of the single argument range(...) that enum values could not
be used without casting. I would like to see this being backported to 2.6.

See merge request [!553]

  [!553]: gitlab.dune-project.org/core/dune-common/merge_requests/553


(cherry picked from commit 43772da6)

48c8702f [bugfix] allow single argument `range(...)` with enum values

Merge branch 'bugfix/add_to_unique_ptr_to_CmakeLists' into 'master'

Header was missing in CMakeLists.txt and now breaks code due to usage in
dune-grid Needs to be backported to 2.6

See merge request [!547]

  [!547]: gitlab.dune-project.org/core/dune-common/merge_requests/547


(cherry picked from commit 709ea8aa)

53f306b7 added missing header to_unique_ptr.hh to CMakeLists.txt

This backports the new options for virtualenv placement to the 2.6 release. While the change is not overly
important in everyday use, it is really important for testing modules that use dune-testtools.

I changed the default for `DUNE_PYTHON_EXTERNAL_VIRTUALENV_FOR_ABSOLUTE_BUILDDIR` to `OFF` so that users don't
get an unexpected change in behavior on the release branch.

See merge request !544
See merge request !545

As we don't want to change the default behavior on a release branch, require users to explicitly
enable the new placement for the 2.6 release.

The current logic for placing / locating the virtualenv is rather flaky in combination with
installed modules or when `DUNE_PYTHON_VIRTUALENV_SETUP` was not enabled for all modules (as happens
in the CI images).

This MR improves the situation in two ways:

- It allows users to explicitly set `DUNE_PYTHON_VIRTUALENV_PATH` when running CMake. The build
  system will then use the given path for the virtualenv instead of guessing a location.

- When using an absolute build directory with dunecontrol, the virtualenv will no longer be placed
  inside the build directory of any module, but in the dedicated top-level directory
  `dune-python-env` inside the build directory root. This behavior can be disabled by setting
  `DUNE_PYTHON_EXTERNAL_VIRTUALENV_FOR_ABSOLUTE_BUILDDIR=0`.

See merge request !544

While this change adds new features to the 2.6 release, it is required to later create a stable configuration for CI modules that use dune-testtools.

See merge request !542

See merge request !543

Knowing whether `dunecontrol` was invoked with an absolute build directory can be very useful in CMake, as we can then place state that is shared between multiple modules directly in the build directory, e.g. the Python virtualenv.

See merge request !542

See merge request !541

pip 10 moved several interfaces to an internal package, causing our pyversion.py script to fail.
This patches fixes the issue by getting installed distributions directly from setuptools, as
suggested in https://github.com/pypa/pip/issues/5243.

See merge request !540

(cherry picked from commit 746aa626)

2443bc4a Make Python package detection work with pip 10

See merge request !539

See merge request !538

(cherry picked from commit 63b46abe)

2dddd6e0 Run one test job with disabled assertions

See merge request !537

When the virtualenv support was added to the build system,
https://bugs.launchpad.net/debian/+source/python3.4/+bug/1290847# made us bail out
completely on building a virtualenv with preinstalled pip. The situation has improved
a lot since then; even Ubuntu 14.04 gets this right now as long as you install the
right packages. So let's be nice to our users and try whether installing pip works
before forcing them to do it manually or use `get-pip`. If a user insists on `get-pip`
by setting `DUNE_PYTHON_ALLOW_GET_PIP`, we skip this additional step and keep using
`get-pip`.

This shouldn't break anything, so I'll backport it to 2.6 as well, as it should make
it much easier to use the virtualenv in CI images (e.g. for
`dune-pdelab-systemtesting`, which requires `dune-testtools`).

See merge request !536

(cherry picked from commit 7e856817)

99f05bb7 Try to install Python virtualenv with pip before forcing get-pip onto users
92bf4520 Update documentation
1e9ae690 Create virtualenv during CI tests

See merge request !532