src/main/java/dev/frogmc/frogloader/impl/SemVerParseException.java

@@ -4,6 +4,6 @@ import java.io.IOException;
 
 public class SemVerParseException extends IOException {
 	public SemVerParseException(String message) {
-		super("Failed to parse SemVer: " + message);
+		super("Failed to parse SemVer: `" + message + "`");
 	}
 }

src/main/java/dev/frogmc/frogloader/impl/mod/SemVerImpl.java

@@ -9,12 +9,14 @@ import java.util.regex.Pattern;
 import dev.frogmc.frogloader.api.mod.SemVer;
 import dev.frogmc.frogloader.impl.SemVerParseException;
 import lombok.NonNull;
+import lombok.SneakyThrows;
+import org.jetbrains.annotations.Nullable;
 
 public record SemVerImpl(int major, int minor, int patch, String prerelease, String build) implements SemVer {
 	// Adapted from https://semver.org/#is-there-a-suggested-regular-expression-regex-to-check-a-semver-string
 	private static final Pattern SEMVER_PATTERN = Pattern.compile("^(?<major>0|[1-9]\\d*)\\." +
-																  "(?<minor>0|[1-9]\\d*)\\." +
-																  "(?<patch>0|[1-9]\\d*)" +
+																  "(?<minor>0|[1-9]\\d*)" +
+																  "(\\.(?<patch>0|[1-9]\\d*))?" +
 																  "(?:-(?<prerelease>(?:0|[1-9]\\d*|\\d*[a-zA-Z-][0-9a-zA-Z-]*)" +
 																  "(?:\\.(?:0|[1-9]\\d*|\\d*[a-zA-Z-][0-9a-zA-Z-]*))*))?" +
 																  "(?:\\+(?<buildmetadata>[0-9a-zA-Z-]+(?:\\.[0-9a-zA-Z-]+)*))?$");
@@ -27,7 +29,9 @@ public record SemVerImpl(int major, int minor, int patch, String prerelease, Str
 
 		int major = Integer.parseInt(matcher.group("major"));
 		int minor = Integer.parseInt(matcher.group("minor"));
-		int patch = Integer.parseInt(matcher.group("patch"));
+		// minecraft treats the `patch` component as optional...
+		@Nullable String patchString = matcher.group("patch");
+		int patch = patchString == null ? 0 : Integer.parseInt(matcher.group("patch"));
 		String prerelease = matcher.group("prerelease");
 		String buildmetadata = matcher.group("buildmetadata");
 		return new SemVerImpl(major, minor, patch, prerelease, buildmetadata);