internal/rosa/python: extra script after install

This is generally for test suite, due to the lack of standard or widely agreed upon convention.

Signed-off-by: Ophestra <cat@gensokyo.uk>

internal/rosa/meson.go

@@ -10,26 +10,15 @@ import (
 func (t Toolchain) newMeson() (pkg.Artifact, string) {
 	const (
 		version  = "1.11.0"
-		checksum = "b7oo3U_cklhzsTfsyYsjPGyeEufiS-Pm06JPLzodseS125Ach62ZBly7R6dSDiAc"
+		checksum = "QJolMPzypTiS65GReSNPPlkUjHI6b1EDpZ-avIk3n6b6TQ93KfUM57DVUpY97Hf7"
 	)
-	return t.New("meson-"+version, 0, []pkg.Artifact{
-		t.Load(Zlib),
-		t.Load(Python),
-		t.Load(Setuptools),
-	}, nil, nil, `
-cd /usr/src/meson
-chmod -R +w meson.egg-info
-python3 setup.py \
-	install \
-	--prefix=/system \
-	--root=/work
-`, pkg.Path(AbsUsrSrc.Append("meson"), true, newFromGitHubRelease(
+	return t.NewPackage("meson", version, newFromGitHub(
 		"mesonbuild/meson",
 		version,
-		"meson-"+version+".tar.gz",
 		checksum,
-		pkg.TarGzip,
-	))), version
+	), nil, (*PipHelper)(nil),
+		Setuptools,
+	), version
 }
 func init() {
 	artifactsM[Meson] = Metadata{

internal/rosa/python.go

@@ -81,6 +81,62 @@ func init() {
 	}
 }
 
+// PipHelper is the [Python] pip packaging helper.
+type PipHelper struct {
+	// Whether to omit --no-build-isolation.
+	BuildIsolation bool
+	// Whether to enter source after install.
+	EnterSource bool
+	// Runs after install.
+	Script string
+}
+
+var _ Helper = new(PipHelper)
+
+// extra returns python.
+func (*PipHelper) extra(int) P { return P{Python} }
+
+// wantsChmod returns true.
+func (*PipHelper) wantsChmod() bool { return true }
+
+// wantsWrite is equivalent to wantsChmod.
+func (attr *PipHelper) wantsWrite() bool { return attr.wantsChmod() }
+
+// scriptEarly is a noop.
+func (*PipHelper) scriptEarly() string { return "" }
+
+// createDir returns false.
+func (*PipHelper) createDir() bool { return false }
+
+// wantsDir requests a new directory in TMPDIR.
+func (*PipHelper) wantsDir() string { return `"$(mktemp -d)"` }
+
+// script generates the pip3 install command.
+func (attr *PipHelper) script(name string) string {
+	if attr == nil {
+		attr = new(PipHelper)
+	}
+
+	var extra string
+	if !attr.BuildIsolation {
+		extra += `
+	--no-build-isolation \`
+	}
+
+	script := attr.Script
+	if attr.EnterSource {
+		script = "cd '/usr/src/" + name + "'\n" + script
+	}
+
+	return `
+pip3 install \
+	--no-index \
+	--prefix=/system \
+	--root=/work \` + extra + `
+	'/usr/src/` + name + `'
+` + script
+}
+
 // newViaPip installs a pip wheel from a url.
 func (t Toolchain) newViaPip(
 	name, version, url, checksum string,
@@ -134,18 +190,12 @@ func (t Toolchain) newSetuptools() (pkg.Artifact, string) {
 		version  = "82.0.1"
 		checksum = "nznP46Tj539yqswtOrIM4nQgwLA1h-ApKX7z7ghazROCpyF5swtQGwsZoI93wkhc"
 	)
-	return t.New("setuptools-"+version, 0, t.AppendPresets(nil,
-		Python,
-	), nil, nil, `
-pip3 install \
-	--no-index \
-	--prefix=/system \
-	--root=/work \
-	/usr/src/setuptools
-`, pkg.Path(AbsUsrSrc.Append("setuptools"), true, newFromGitHub(
+	return t.NewPackage("setuptools", version, newFromGitHub(
 		"pypa/setuptools",
 		"v"+version, checksum,
-	))), version
+	), nil, &PipHelper{
+		BuildIsolation: true,
+	}), version
 }
 func init() {
 	artifactsM[Setuptools] = Metadata{