Install alpm hook recommending `gu rebuild libpolyglot`

Apparently the only reason that the `node --polyglot` added to test.sh
in the previous commit worked on my system is that it silently fell back
to `node --polyglot --jvm`; however, it’s *supposed* to run polyglot
Node + everything else as a native image, without a JVM. And apparently,
R can’t be built as a native image (for engineering reasons, I’ve been
told), so if it doesn’t fall back to --jvm mode, then our test doesn’t
work. Consequently, we should actually specify --polyglot --jvm.

The fallback happens when libpolyglot.so is missing. It’s supposed to be
built by `gu rebuild libpolyglot`, and apparently `gu` prints a message
recommending that you run this command when you use it to install a new
language; since we bypass gu, we should print a similar message in our
package installation process. We don’t directly run the command for the
same reason that gu doesn’t: it’s way too expensive, requiring over four
hours of CPU time on my system. Even as a hook, rather than a
post-install script (i.e. only running once at the end of all package
installs, not once per package), I can’t justify this expenditure for
everyone installing the package, especially since most people probably
won’t need this (evidently I’ve been using GraalVM for years without
ever having built libpolyglot.so). So we just make the hook print a
message for users, and they can hopefully decide for themselves if they
want to run the command or not. (If people ask about the message in the
AUR comments, we can probably iterate on the phrasing a bit.)

4 files changed, 22 insertions, 5 deletions

diff --git a/.SRCINFO b/.SRCINFO
index 4deb9309a900..e38cb88ebb47 100644
--- a/.SRCINFO
+++ b/.SRCINFO
@@ -1,7 +1,7 @@
 pkgbase = jdk8-graalvm-bin
 	pkgdesc = Universal virtual machine for running applications written in a variety of languages (JVM-based, LLVM-based, or other), Java 8 version
 	pkgver = 21.2.0
-	pkgrel = 1
+	pkgrel = 2
 	url = https://www.graalvm.org/
 	install = jdk8-graalvm-bin.install
 	arch = x86_64
@@ -12,6 +12,8 @@ pkgbase = jdk8-graalvm-bin
 	provides = java-runtime=8
 	provides = java-environment=8
 	source = https://github.com/graalvm/graalvm-ce-builds/releases/download/vm-21.2.0/graalvm-ce-java8-linux-amd64-21.2.0.tar.gz
+	source = graalvm-rebuild-libpolyglot.hook
 	sha256sums = 0ea16ff2fe178800195e2918ee7ceee352601d4161a17eac67979febaaecfe05
+	sha256sums = SKIP
 
 pkgname = jdk8-graalvm-bin
diff --git a/PKGBUILD b/PKGBUILD
index 4912879470de..abc54a07e127 100644
--- a/PKGBUILD
+++ b/PKGBUILD
@@ -3,7 +3,7 @@
 java_=8
 pkgname="jdk${java_}-graalvm-bin"
 pkgver=21.2.0
-pkgrel=1
+pkgrel=2
 pkgdesc="Universal virtual machine for running applications written in a variety of languages (JVM-based, LLVM-based, or other), Java ${java_} version"
 arch=('x86_64')
 url='https://www.graalvm.org/'
@@ -15,12 +15,16 @@ optdepends=("graal-nodejs-jdk${java_}-bin: Node.js component (used to be bundled
 provides=("java-runtime=${java_}"
           "java-environment=${java_}")
 install="$pkgname.install"
-source=("https://github.com/graalvm/graalvm-ce-builds/releases/download/vm-${pkgver}/graalvm-ce-java${java_}-linux-amd64-${pkgver}.tar.gz")
-sha256sums=('0ea16ff2fe178800195e2918ee7ceee352601d4161a17eac67979febaaecfe05')
+source=("https://github.com/graalvm/graalvm-ce-builds/releases/download/vm-${pkgver}/graalvm-ce-java${java_}-linux-amd64-${pkgver}.tar.gz"
+        'graalvm-rebuild-libpolyglot.hook')
+sha256sums=('0ea16ff2fe178800195e2918ee7ceee352601d4161a17eac67979febaaecfe05'
+            'SKIP')
 
 package() {
     cd "graalvm-ce-java${java_}-${pkgver}"
     mkdir -p "$pkgdir/usr/lib/jvm/java-${java_}-graalvm/"
     cp -a -t "$pkgdir/usr/lib/jvm/java-${java_}-graalvm/" *
     install -DTm644 LICENSE.txt "$pkgdir/usr/share/licenses/$pkgname/LICENSE"
+    sed "s/JAVA/${java_}/g" < "../graalvm-rebuild-libpolyglot.hook" > "graalvm-jdk${java_}-rebuild-libpolyglot.hook"
+    install -DTm644 "graalvm-jdk${java_}-rebuild-libpolyglot.hook" "$pkgdir/usr/share/libalpm/hooks/graalvm-jdk${java_}-rebuild-libpolyglot.hook"
 }
diff --git a/graalvm-rebuild-libpolyglot.hook b/graalvm-rebuild-libpolyglot.hook
new file mode 100644
index 000000000000..9f35151d15ab
--- /dev/null
+++ b/graalvm-rebuild-libpolyglot.hook
@@ -0,0 +1,11 @@
+[Trigger]
+Type = Path
+Operation = Install
+Operation = Upgrade
+Operation = Remove
+Target = usr/lib/jvm/java-JAVA-graalvm/*
+
+[Action]
+Description = Suggest rebuilding GraalVM libpolyglot component
+When = PostTransaction
+Exec = /usr/bin/printf '%s\n' 'Changes to GraalVM detected.' 'You may need to rebuild libpolyglot (and possibly other components) with the following command:' '  /usr/lib/jvm/java-JAVA-graalvm/bin/gu rebuild libpolyglot' "Note that this will take a while (which is why it's not done automatically):" 'the package maintainer has experienced CPU times upwards of _four hours_.' '(However, it parallelizes fairly well, so wall-clock time will depend on your CPU.)' "If you don't rebuild libpolyglot, then --polyglot without --jvm probably won't work right."
diff --git a/test.sh b/test.sh
index 0b6209c3adcf..08bddea83689 100755
--- a/test.sh
+++ b/test.sh
@@ -15,7 +15,7 @@ PATH=/usr/lib/jvm/java-${java_}-graalvm/bin/:$(systemd-path search-binaries-defa
 
 printf '%s\n' 'Testing Node with polyglot R, Python, Ruby, JavaScript, and Java...'
 
-jsThree=$(node --polyglot << 'EOF'
+jsThree=$(node --polyglot --jvm << 'EOF'
 rPlus = Polyglot.eval('R', '(function(s1, s2) s1 + s2)');
 pythonPlus = Polyglot.eval('python', 'lambda s1, s2: s1 + s2');
 rubyOne = Polyglot.eval('ruby', '1')