Try this maybe?

asottile · web-flow · commit d5a49100cf85 · 2020-07-31T21:44:44.000-07:00
diff --git a/pyproject.toml b/pyproject.toml
@@ -2,7 +2,7 @@
 requires = [
   # sync with setup.py until we discard non-pep-517/518
   "setuptools>=42.0",
-  "setuptools-scm>=3.4",
+  "setuptools-scm[toml]>=3.4",
   "wheel",
 ]
 build-backend = "setuptools.build_meta"

Original file line number	Diff line number	Diff line change
`@@ -2,7 +2,7 @@`
`2`	`2`	`requires = [`
`3`	`3`	`# sync with setup.py until we discard non-pep-517/518`
`4`	`4`	`"setuptools>=42.0",`
`5`		`- "setuptools-scm>=3.4",`
	`5`	`+ "setuptools-scm[toml]>=3.4",`
`6`	`6`	`"wheel",`
`7`	`7`	`]`
`8`	`8`	`build-backend = "setuptools.build_meta"`