diff --git a/.github/workflows/ci-additional.yaml b/.github/workflows/ci-additional.yaml
index 7087b43abc3..8f84b021952 100644
--- a/.github/workflows/ci-additional.yaml
+++ b/.github/workflows/ci-additional.yaml
@@ -72,7 +72,10 @@ jobs:
           python xarray/util/print_versions.py
       - name: Run doctests
         run: |
-          python -m pytest --doctest-modules xarray --ignore xarray/tests
+          # Raise an error if there are warnings in the doctests, with `-Werror`.
+          # This is a trial; if it presents an problem, feel free to remove.
+          # See https://github.com/pydata/xarray/issues/7164 for more info.
+          python -m pytest --doctest-modules xarray --ignore xarray/tests -Werror
 
   mypy:
     name: Mypy
diff --git a/doc/whats-new.rst b/doc/whats-new.rst
index f13f0b80a6c..aefb6adfc2b 100644
--- a/doc/whats-new.rst
+++ b/doc/whats-new.rst
@@ -50,6 +50,9 @@ Documentation
 
 Internal Changes
 ~~~~~~~~~~~~~~~~
+- Doctests fail on any warnings (:pull:`7166`)
+  By `Maximilian Roos <https://github.com/max-sixty>`_.
+
 
 
 .. _whats-new.2022.10.0:
diff --git a/xarray/backends/rasterio_.py b/xarray/backends/rasterio_.py
index d3153eb3e18..acd9070320b 100644
--- a/xarray/backends/rasterio_.py
+++ b/xarray/backends/rasterio_.py
@@ -187,49 +187,6 @@ def open_rasterio(
     <http://web.archive.org/web/20160326194152/http://remotesensing.org/geotiff/spec/geotiff2.5.html#2.5.2>`_
     for more information).
 
-    You can generate 2D coordinates from the file's attributes with::
-
-        >>> from affine import Affine
-        >>> da = xr.open_rasterio(
-        ...     "https://github.com/rasterio/rasterio/raw/1.2.1/tests/data/RGB.byte.tif"
-        ... )
-        >>> da
-        <xarray.DataArray (band: 3, y: 718, x: 791)>
-        [1703814 values with dtype=uint8]
-        Coordinates:
-          * band     (band) int64 1 2 3
-          * y        (y) float64 2.827e+06 2.826e+06 2.826e+06 ... 2.612e+06 2.612e+06
-          * x        (x) float64 1.021e+05 1.024e+05 1.027e+05 ... 3.389e+05 3.392e+05
-        Attributes:
-            transform:      (300.0379266750948, 0.0, 101985.0, 0.0, -300.041782729805...
-            crs:            +init=epsg:32618
-            res:            (300.0379266750948, 300.041782729805)
-            is_tiled:       0
-            nodatavals:     (0.0, 0.0, 0.0)
-            scales:         (1.0, 1.0, 1.0)
-            offsets:        (0.0, 0.0, 0.0)
-            AREA_OR_POINT:  Area
-        >>> transform = Affine(*da.attrs["transform"])
-        >>> transform
-        Affine(300.0379266750948, 0.0, 101985.0,
-               0.0, -300.041782729805, 2826915.0)
-        >>> nx, ny = da.sizes["x"], da.sizes["y"]
-        >>> x, y = transform * np.meshgrid(np.arange(nx) + 0.5, np.arange(ny) + 0.5)
-        >>> x
-        array([[102135.01896334, 102435.05689001, 102735.09481669, ...,
-                338564.90518331, 338864.94310999, 339164.98103666],
-               [102135.01896334, 102435.05689001, 102735.09481669, ...,
-                338564.90518331, 338864.94310999, 339164.98103666],
-               [102135.01896334, 102435.05689001, 102735.09481669, ...,
-                338564.90518331, 338864.94310999, 339164.98103666],
-               ...,
-               [102135.01896334, 102435.05689001, 102735.09481669, ...,
-                338564.90518331, 338864.94310999, 339164.98103666],
-               [102135.01896334, 102435.05689001, 102735.09481669, ...,
-                338564.90518331, 338864.94310999, 339164.98103666],
-               [102135.01896334, 102435.05689001, 102735.09481669, ...,
-                338564.90518331, 338864.94310999, 339164.98103666]])
-
     Parameters
     ----------
     filename : str, rasterio.DatasetReader, or rasterio.WarpedVRT
diff --git a/xarray/core/dataarray.py b/xarray/core/dataarray.py
index fe761dafa7b..8d971c53917 100644
--- a/xarray/core/dataarray.py
+++ b/xarray/core/dataarray.py
@@ -5261,9 +5261,9 @@ def idxmin(
         >>> array.min()
         <xarray.DataArray ()>
         array(-2)
-        >>> array.argmin()
-        <xarray.DataArray ()>
-        array(4)
+        >>> array.argmin(...)
+        {'x': <xarray.DataArray ()>
+        array(4)}
         >>> array.idxmin()
         <xarray.DataArray 'x' ()>
         array('e', dtype='<U1')
@@ -5357,9 +5357,9 @@ def idxmax(
         >>> array.max()
         <xarray.DataArray ()>
         array(2)
-        >>> array.argmax()
-        <xarray.DataArray ()>
-        array(1)
+        >>> array.argmax(...)
+        {'x': <xarray.DataArray ()>
+        array(1)}
         >>> array.idxmax()
         <xarray.DataArray 'x' ()>
         array('b', dtype='<U1')
@@ -5450,9 +5450,6 @@ def argmin(
         >>> array.min()
         <xarray.DataArray ()>
         array(-1)
-        >>> array.argmin()
-        <xarray.DataArray ()>
-        array(2)
         >>> array.argmin(...)
         {'x': <xarray.DataArray ()>
         array(2)}
@@ -5555,9 +5552,6 @@ def argmax(
         >>> array.max()
         <xarray.DataArray ()>
         array(3)
-        >>> array.argmax()
-        <xarray.DataArray ()>
-        array(3)
         >>> array.argmax(...)
         {'x': <xarray.DataArray ()>
         array(3)}