The process tests do not build with gcc: a test's reader shadows itself #229

What goes wrong

Main's check on dff8e53 (#227) fails: the gcc-debug tree does not build.

modules/process/tests/child_test.cpp:159:37: error: declaration of 'kRead' shadows a previous local [-Werror=shadow]
FAILED: gcc-debug build
check full FAILED (1) in 813s

In AChildIsNotGivenTheVariablesWithheldFromIt, the lambda kRead declares its output path under the same name, kRead. gcc 14 counts that as shadowing the enclosing local under -Wshadow; clang does not. A pull request's check builds the clang trees only, so #227 passed it, and the failure showed first on main's full tier. Every check of main fails the same way until it is fixed.

What should happen

The test names its output path apart from the lambda, and gcc-debug builds again.