Temporarily change contents of an existing
- new, .new
New variables and their values
Code to execute in the temporary environment
- path, .path
location of existing
Makevarsfile to modify.
- assignment, .assignment
assignment type to use.
Additional new variables and their values.
The environment to use for scoping.
Makevars file exists or the fields in
not exist in the existing
Makevars file then the fields are added to
the new file. Existing fields which are not included in
appended unchanged. Fields which exist in
Makevars and in
are modified to use the value in
withr for examples