Replace env in binaryDir preset.

[dlyr]

I use it with

	    "binaryDir": "$env{BUILD_POOL_PREFIX}/${presetName}"

and something to set env before build

  (defun dlyr/dir-name-function (project-root)
    "Return the directory name to run CMake in based on PROJECT-ROOT."
    (replace-regexp-in-string "[-/= #]" "_"  (concat (expand-file-name project-root)
						     (if (fboundp 'magit-get-current-branch) (magit-get-current-branch) ""))))


  (defun dlyr/cmake-setup-env-vars (&optional _)
    "Automatically set env BUILD_POOL_PREFIX and GIT_BRANCH env vars before running cmake."
    (if-let* ((project (project-current))
              (project-root (project-root project))
              (build-dir (dlyr/dir-name-function project-root))
              (prefix (or dlyr/cmake-build-pool-dir "build-pool")))
        (setenv "BUILD_POOL_PREFIX" (concat prefix build-dir))
    (setenv "BUILD_POOL_PREFIX" "local-build-pool")))

(advice-add 'cmake-integration-cmake-reconfigure :before #'dlyr/cmake-setup-env-vars)