diff --git a/lua/git/cmd.lua b/lua/git/cmd.lua
index 2783ba9..ae710be 100644
--- a/lua/git/cmd.lua
+++ b/lua/git/cmd.lua
@@ -20,15 +20,17 @@ local cached_cmds
 
 ---@param result vim.SystemCompleted
 local function populate_cached_cmds(result)
-    cached_cmds = {}
-    if result.code == 0 then
-        for line in (result.stdout or ""):gmatch("[^\r\n]+") do
-            if line ~= "" then
-                table.insert(cached_cmds, line)
-            end
-        end
-        table.sort(cached_cmds)
+    if result.code ~= 0 then
+        log.error("git --list-cmds failed: %s", vim.trim(result.stderr or ""))
+        return
     end
+    cached_cmds = {}
+    for line in (result.stdout or ""):gmatch("[^\r\n]+") do
+        if line ~= "" then
+            table.insert(cached_cmds, line)
+        end
+    end
+    table.sort(cached_cmds)
 end
 
 ---Prime `cached_cmds` asynchronously so the first `:G <Tab>` doesn't block.
@@ -111,6 +113,13 @@ local function run_in_split(worktree, args, conf)
             vim.api.nvim_buf_set_lines(buf, 0, -1, false, split_lines(content))
             vim.bo[buf].modifiable = false
             vim.bo[buf].modified = false
+            if obj.code ~= 0 then
+                log.error(
+                    "git %s failed: %s",
+                    args[1] or "",
+                    vim.trim(obj.stderr or "")
+                )
+            end
         end)
     end)
 end
diff --git a/lua/git/commit.lua b/lua/git/commit.lua
index 4c7882f..f5956f7 100644
--- a/lua/git/commit.lua
+++ b/lua/git/commit.lua
@@ -25,6 +25,8 @@ function M.commit(opts)
         ):wait()
         if result.code == 0 then
             initial = (result.stdout or ""):gsub("\n+$", "")
+        else
+            log.warning("git log -1 failed: %s", vim.trim(result.stderr or ""))
         end
     end
 
diff --git a/lua/git/diff.lua b/lua/git/diff.lua
index f6a97be..a8170cf 100644
--- a/lua/git/diff.lua
+++ b/lua/git/diff.lua
@@ -62,8 +62,19 @@ local function read_show(worktree, revspec)
         { cwd = worktree, text = true }
     )
         :wait()
-    local content = result.code == 0 and (result.stdout or "") or ""
-    local lines = vim.split(content, "\n", { plain = true, trimempty = false })
+    if result.code ~= 0 then
+        log.error(
+            "git show %s failed: %s",
+            revspec,
+            vim.trim(result.stderr or "")
+        )
+        return {}
+    end
+    local lines = vim.split(
+        result.stdout or "",
+        "\n",
+        { plain = true, trimempty = false }
+    )
     if #lines > 0 and lines[#lines] == "" then
         table.remove(lines)
     end
diff --git a/lua/git/repo.lua b/lua/git/repo.lua
index 4d39f55..e844930 100644
--- a/lua/git/repo.lua
+++ b/lua/git/repo.lua
@@ -1,3 +1,4 @@
+local log = require("log")
 local util = require("util")
 
 local UNMERGED = {
@@ -73,6 +74,7 @@ local function resolve(path)
     f:close()
     local gitdir = content:match("gitdir:%s*(%S+)")
     if not gitdir then
+        log.warning(".git file at %s has no `gitdir:` line", found)
         return nil
     end
     if not gitdir:match("^/") then
@@ -148,6 +150,8 @@ local function do_refresh(repo)
                     statuses[vim.fs.joinpath(repo.worktree, path_part)] =
                         format(code)
                 end
+            else
+                log.warning("git status failed: %s", vim.trim(obj.stderr or ""))
             end
             local dirty = false
             for buf in pairs(repo.buffers) do
diff --git a/lua/git/status_win.lua b/lua/git/status_win.lua
index e465347..465e00a 100644
--- a/lua/git/status_win.lua
+++ b/lua/git/status_win.lua
@@ -145,6 +145,9 @@ local function fetch_status(worktree, callback)
                 Unpushed = {},
                 Unpulled = {},
             }
+            if obj.code ~= 0 then
+                log.error("git status failed: %s", vim.trim(obj.stderr or ""))
+            end
             if obj.code == 0 then
                 for line in (obj.stdout or ""):gmatch("[^\r\n]+") do
                     if line:sub(1, 2) == "##" then
@@ -237,6 +240,12 @@ local function fetch_status(worktree, callback)
                                     })
                                 end
                             end
+                        else
+                            log.error(
+                                "git log %s failed: %s",
+                                f.range,
+                                vim.trim(log_obj.stderr or "")
+                            )
                         end
                         pending = pending - 1
                         if pending == 0 then
@@ -643,7 +652,17 @@ local function action_stage()
     if entry.section == "Staged" then
         return
     end
-    vim.system({ "git", "add", "--", entry.path }, { cwd = s.worktree })
+    vim.system(
+        { "git", "add", "--", entry.path },
+        { cwd = s.worktree },
+        function(obj)
+            if obj.code ~= 0 then
+                vim.schedule(function()
+                    log.error("git add failed: %s", vim.trim(obj.stderr or ""))
+                end)
+            end
+        end
+    )
 end
 
 local function action_unstage()
@@ -660,7 +679,16 @@ local function action_unstage()
         table.insert(cmd, entry.orig)
     end
     table.insert(cmd, entry.path)
-    vim.system(cmd, { cwd = s.worktree })
+    vim.system(cmd, { cwd = s.worktree }, function(obj)
+        if obj.code ~= 0 then
+            vim.schedule(function()
+                log.error(
+                    "git restore --staged failed: %s",
+                    vim.trim(obj.stderr or "")
+                )
+            end)
+        end
+    end)
 end
 
 local function action_discard()
@@ -678,7 +706,10 @@ local function action_discard()
     if entry.section == "Untracked" then
         prompt = string.format("Delete untracked file %s?", entry.path)
         action = function()
-            os.remove(vim.fs.joinpath(s.worktree, entry.path))
+            local ok, err = os.remove(vim.fs.joinpath(s.worktree, entry.path))
+            if not ok then
+                log.error("failed to remove %s: %s", entry.path, err or "")
+            end
             refresh(vim.api.nvim_get_current_buf())
         end
     elseif entry.section == "Unstaged" then
@@ -686,7 +717,17 @@ local function action_discard()
         action = function()
             vim.system(
                 { "git", "checkout", "--", entry.path },
-                { cwd = s.worktree }
+                { cwd = s.worktree },
+                function(obj)
+                    if obj.code ~= 0 then
+                        vim.schedule(function()
+                            log.error(
+                                "git checkout failed: %s",
+                                vim.trim(obj.stderr or "")
+                            )
+                        end)
+                    end
+                end
             )
         end
     else