From 4f3e57ef13d0ad4c00d0a87f0858cde81456a2e0 Mon Sep 17 00:00:00 2001 From: Jonathan Tan Date: Mon, 2 Dec 2019 11:57:52 -0800 Subject: [PATCH] submodule--helper: advise on fatal alternate error When recursively cloning a superproject with some shallow modules defined in its .gitmodules, then recloning with "--reference=", 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 '' cannot add alternate: reference repository '' 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 Acked-by: Jeff King Signed-off-by: Junio C Hamano --- Documentation/config/advice.txt | 3 +++ advice.c | 2 ++ advice.h | 1 + builtin/submodule--helper.c | 10 ++++++++++ 4 files changed, 16 insertions(+) diff --git a/Documentation/config/advice.txt b/Documentation/config/advice.txt index 6aaa360202..d4e698cd3f 100644 --- a/Documentation/config/advice.txt +++ b/Documentation/config/advice.txt @@ -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. -- diff --git a/advice.c b/advice.c index 3ee0ee2d8f..249c60dcf3 100644 --- a/advice.c +++ b/advice.c @@ -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 } diff --git a/advice.h b/advice.h index d015404843..b706780614 100644 --- a/advice.h +++ b/advice.h @@ -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))) diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c index 2c2395a620..12d546dfbb 100644 --- a/builtin/submodule--helper.c +++ b/builtin/submodule--helper.c @@ -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: