- `awk`
- `cat`
+- `cd`
- `cksum`
- `cp`
- `date`
+- `diff`
- `file`
- `find`
- `git` (optional; set `GIT=` to disable)
- `grep`
- `ln`
-- `ls`
- `mkdir`
- `mv`
- `od`
The current version of the source files (default: derived from the
current git tag/branch/commit).
+- **`QUIET`:**
+ If this variable has a value, informative messages will not be
+ printed (default: empty).
+ Informative messages print to stderr, not stdout, so disabling them
+ usually shouldn’t be necessary.
+ This does not (cannot) disable messages from Make itself, for which
+ the `-s`, `--silent` ∕ `--quiet` Make option is more likely to be
+ useful.
+
- **`VERBOSE`:**
If this variable has a value, every recipe instruction will be
printed when it runs (default: empty).
- **`SRCTIME`:**
The time at which the source file was last modified.
- Due to limitations in Posix, this time will only have minute
- precision if the file was modified in the last six months, and will
- only have day precision if the file is older.
- Users should not expect this value to be particularly stable.
- **`THISREV`:**
The value of the `THISREV` variable (if present).