qt-5/hooks/fix-qt-builtin-paths.sh: do not hardcode output paths

The fix-qt-builtin-paths.sh script replaces several strings in *.pr*
files with output names; for example

```
$$[QT_HOST_BINS]    is replaced by    $dev
```

This causes problems when cross-compiling: the `mkspecs/qconfig.pri`
in the `$dev` output of `qtbase` will have output names *of qtbase*
hardwired into it.  Since `qmake` is part of the `qtbase` package,
it will pick up these hardcoded paths when compiling the other
modules.

As a result, the `installPhase` of `qtdeclarative` (and other
modules) will attempt to copy their results into the
already-registered store path for `qtbase`.  This will fail, because
Nix prevents writes to a storepath after it has been registered.

Fortunately the `.pri` files understand environment variable
substitution: you can write `$$NIX_OUTPUT_DEV` to tell `qmake` that
it should use the value of the `NIX_OUTPUT_DEV` environment variable
*at `qmake`-run-time* (rather than at `qmake`-build-time).

0 files changed, 0 insertions, 0 deletions