give more helpful error messages

src/archive.c

@@ -276,6 +276,9 @@ int apk_archive_entry_extract(struct apk_archive_entry *ae, const char *fn)
 			r = chown(fn, ae->uid, ae->gid);
 		else
 			r = lchown(fn, ae->uid, ae->gid);
+		if (r < 0)
+			apk_error("Failed to set ownership on %s: %s", fn, 
+					strerror(errno));
 	} else {
 		apk_error("Failed to extract %s\n", ae->name);
 	}

src/database.c

@@ -434,8 +434,10 @@ static int apk_db_read_config(struct apk_database *db)
 	fchdir(db->root_fd);
 
 	fd = open("var/lib/apk/world", O_RDONLY);
-	if (fd < 0)
+	if (fd < 0) {
+		apk_error("Please run 'apk create' to initialize root");
 		return -1;
+	}
 
 	fstat(fd, &st);
 	buf = malloc(st.st_size);
@@ -470,6 +472,7 @@ int apk_db_open(struct apk_database *db, const char *root)
 		db->root = strdup(root);
 		db->root_fd = open(root, O_RDONLY);
 		if (db->root_fd < 0) {
+			apk_error("%s: %s", root, strerror(errno));
 			free(db->root);
 			return -1;
 		}
@@ -791,8 +794,10 @@ int apk_db_install_pkg(struct apk_database *db,
 		 db->repos[0].url, newpkg->name->name, newpkg->version);
 
 	fd = open(file, O_RDONLY);
-	if (fd < 0)
+	if (fd < 0) {
+		apk_error("%s: %s", file, strerror(errno));
 		return errno;
+	}
 
 	fcntl(fd, F_SETFD, FD_CLOEXEC);
 

src/package.c

@@ -9,6 +9,7 @@
  * by the Free Software Foundation. See http://www.gnu.org/ for details.
  */
 
+#include <errno.h>
 #include <fcntl.h>
 #include <ctype.h>
 #include <stdio.h>
@@ -354,9 +355,11 @@ int apk_pkg_run_script(struct apk_package *pkg, int root_fd,
 		if (pid == -1)
 			return -1;
 		if (pid == 0) {
-			chroot(".");
-			execle(fn, script_types[script->type],
-			       pkg->version, "", NULL, environment);
+			if (chroot(".") < 0) {
+				apk_error("chroot: %s", strerror(errno));
+			} else
+				execle(fn, script_types[script->type],
+				       pkg->version, "", NULL, environment);
 			exit(1);
 		}
 		waitpid(pid, &status, 0);