submodule--helper: advise on fatal alternate error

When recursively cloning a superproject with some shallow modules
defined in its .gitmodules, then recloning with "--reference=<path>", an
error occurs. For example:

  git clone --recurse-submodules --branch=master -j8 \
    https://android.googlesource.com/platform/superproject \
    master
  git clone --recurse-submodules --branch=master -j8 \
    https://android.googlesource.com/platform/superproject \
    --reference master master2

fails with:

  fatal: submodule '<snip>' cannot add alternate: reference repository
  '<snip>' is shallow

When a alternate computed from the superproject's alternate cannot be
added, whether in this case or another, advise about configuring the
"submodule.alternateErrorStrategy" configuration option and using
"--reference-if-able" instead of "--reference" when cloning.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Jonathan Tan 2019-12-02 11:57:52 -08:00 committed by Junio C Hamano
parent 10c64a0b3c
commit 4f3e57ef13
4 changed files with 16 additions and 0 deletions

View File

@ -107,4 +107,7 @@ advice.*::
editor input from the user.
nestedTag::
Advice shown if a user attempts to recursively tag a tag object.
submoduleAlternateErrorStrategyDie:
Advice shown when a submodule.alternateErrorStrategy option
configured to "die" causes a fatal error.
--

View File

@ -30,6 +30,7 @@ int advice_waiting_for_editor = 1;
int advice_graft_file_deprecated = 1;
int advice_checkout_ambiguous_remote_branch_name = 1;
int advice_nested_tag = 1;
int advice_submodule_alternate_error_strategy_die = 1;
static int advice_use_color = -1;
static char advice_colors[][COLOR_MAXLEN] = {
@ -89,6 +90,7 @@ static struct {
{ "graftFileDeprecated", &advice_graft_file_deprecated },
{ "checkoutAmbiguousRemoteBranchName", &advice_checkout_ambiguous_remote_branch_name },
{ "nestedTag", &advice_nested_tag },
{ "submoduleAlternateErrorStrategyDie", &advice_submodule_alternate_error_strategy_die },
/* make this an alias for backward compatibility */
{ "pushNonFastForward", &advice_push_update_rejected }

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@ -30,6 +30,7 @@ extern int advice_waiting_for_editor;
extern int advice_graft_file_deprecated;
extern int advice_checkout_ambiguous_remote_branch_name;
extern int advice_nested_tag;
extern int advice_submodule_alternate_error_strategy_die;
int git_default_advice_config(const char *var, const char *value);
__attribute__((format (printf, 1, 2)))

View File

@ -19,6 +19,7 @@
#include "diffcore.h"
#include "diff.h"
#include "object-store.h"
#include "advice.h"
#define OPT_QUIET (1 << 0)
#define OPT_CACHED (1 << 1)
@ -1268,6 +1269,13 @@ struct submodule_alternate_setup {
#define SUBMODULE_ALTERNATE_SETUP_INIT { NULL, \
SUBMODULE_ALTERNATE_ERROR_IGNORE, NULL }
static const char alternate_error_advice[] = N_(
"An alternate computed from a superproject's alternate is invalid.\n"
"To allow Git to clone without an alternate in such a case, set\n"
"submodule.alternateErrorStrategy to 'info' or, equivalently, clone with\n"
"'--reference-if-able' instead of '--reference'."
);
static int add_possible_reference_from_superproject(
struct object_directory *odb, void *sas_cb)
{
@ -1299,6 +1307,8 @@ static int add_possible_reference_from_superproject(
} else {
switch (sas->error_mode) {
case SUBMODULE_ALTERNATE_ERROR_DIE:
if (advice_submodule_alternate_error_strategy_die)
advise(_(alternate_error_advice));
die(_("submodule '%s' cannot add alternate: %s"),
sas->submodule_name, err.buf);
case SUBMODULE_ALTERNATE_ERROR_INFO: