azure: docker: consistently silence curl but show errors

We currently pass the "--silent" flag to most invocations of curl, but
in fact this does not only suppress the progress meter, but also any
errors. So let's also pass "--show-error", too.

azure-pipelines/coverity.sh

@@ -25,7 +25,7 @@ TOOL_DIR=${BUILD_DIR}/coverity-tools
 if ! test -d "$TOOL_DIR"
 then
     mkdir -p "$TOOL_DIR"
-    curl --silent --location --data "project=libgit2&token=$COVERITY_TOKEN" "$SCAN_TOOL" |
+    curl --silent --show-error --location --data "project=libgit2&token=$COVERITY_TOKEN" "$SCAN_TOOL" |
         tar -xzC "$TOOL_DIR"
     ln -s "$(find "$TOOL_DIR" -type d -name 'cov-analysis*')" "$TOOL_DIR"/cov-analysis
 fi
@@ -44,7 +44,7 @@ COVERITY_UNSUPPORTED=1 \
 tar -czf libgit2.tgz cov-int
 REVISION=$(cd ${SOURCE_DIR} && git rev-parse --short HEAD)
 HTML="$(curl \
-    --silent \
+    --silent --show-error \
     --write-out "\n%{http_code}" \
     --form token="$COVERITY_TOKEN" \
     --form email=libgit2@gmail.com \

azure-pipelines/docker/bionic

@@ -25,9 +25,9 @@ RUN apt-get update && \
 
 FROM apt AS mbedtls
 RUN cd /tmp && \
-    curl --location http://secure.globalsign.com/cacert/gsrsaovsslca2018.crt | openssl x509 -inform der -out /tmp/cacert.pem && \
-    curl --location https://curl.haxx.se/ca/cacert.pem >> /tmp/cacert.pem && \
-    curl --location --silent https://tls.mbed.org/download/mbedtls-2.16.2-apache.tgz --cacert /tmp/cacert.pem | \
+    curl --location --silent --show-error http://secure.globalsign.com/cacert/gsrsaovsslca2018.crt | openssl x509 -inform der -out /tmp/cacert.pem && \
+    curl --location --silent --show-error https://curl.haxx.se/ca/cacert.pem >> /tmp/cacert.pem && \
+    curl --location --silent --show-error https://tls.mbed.org/download/mbedtls-2.16.2-apache.tgz --cacert /tmp/cacert.pem | \
     tar -xz && \
     cd mbedtls-2.16.2 && \
     scripts/config.pl set MBEDTLS_MD4_C 1 && \

azure-pipelines/docker/xenial

@@ -29,9 +29,9 @@ RUN apt-get update && \
 
 FROM apt AS mbedtls
 RUN cd /tmp && \
-    curl --location http://secure.globalsign.com/cacert/gsrsaovsslca2018.crt | openssl x509 -inform der -out /tmp/cacert.pem && \
-    curl --location https://curl.haxx.se/ca/cacert.pem >> /tmp/cacert.pem && \
-    curl --location --silent https://tls.mbed.org/download/mbedtls-2.16.2-apache.tgz --cacert /tmp/cacert.pem | \
+    curl --location --silent --show-error http://secure.globalsign.com/cacert/gsrsaovsslca2018.crt | openssl x509 -inform der -out /tmp/cacert.pem && \
+    curl --location --silent --show-error https://curl.haxx.se/ca/cacert.pem >> /tmp/cacert.pem && \
+    curl --location --silent --show-error https://tls.mbed.org/download/mbedtls-2.16.2-apache.tgz --cacert /tmp/cacert.pem | \
     tar -xz && \
     cd mbedtls-2.16.2 && \
     scripts/config.pl set MBEDTLS_MD4_C 1 && \
@@ -42,7 +42,7 @@ RUN cd /tmp && \
 
 FROM mbedtls AS libssh2
 RUN cd /tmp && \
-    curl --location --silent https://www.libssh2.org/download/libssh2-1.8.2.tar.gz | \
+    curl --location --silent --show-error https://www.libssh2.org/download/libssh2-1.8.2.tar.gz | \
     tar -xz && \
     cd libssh2-1.8.2 && \
     CFLAGS=-fPIC cmake -G Ninja -DBUILD_SHARED_LIBS=ON -DCRYPTO_BACKEND=Libgcrypt . && \
@@ -52,7 +52,7 @@ RUN cd /tmp && \
 
 FROM libssh2 AS valgrind
 RUN cd /tmp && \
-    curl --location --silent https://sourceware.org/pub/valgrind/valgrind-3.15.0.tar.bz2 | \
+    curl --location --silent --show-error https://sourceware.org/pub/valgrind/valgrind-3.15.0.tar.bz2 | \
     tar -xj && \
     cd valgrind-3.15.0 && \
     ./configure && \

azure-pipelines/test.sh

@@ -85,7 +85,7 @@ if [ -z "$SKIP_GITDAEMON_TESTS" ]; then
 fi
 
 if [ -z "$SKIP_PROXY_TESTS" ]; then
-	curl --location --silent https://github.com/ethomson/poxyproxy/releases/download/v0.7.0/poxyproxy-0.7.0.jar >poxyproxy.jar
+	curl --location --silent --show-error https://github.com/ethomson/poxyproxy/releases/download/v0.7.0/poxyproxy-0.7.0.jar >poxyproxy.jar
 
 	echo ""
 	echo "Starting HTTP proxy (Basic)..."
@@ -97,7 +97,7 @@ if [ -z "$SKIP_PROXY_TESTS" ]; then
 fi
 
 if [ -z "$SKIP_NTLM_TESTS" ]; then
-	curl --location --silent https://github.com/ethomson/poxygit/releases/download/v0.4.0/poxygit-0.4.0.jar >poxygit.jar
+	curl --location --silent --show-error https://github.com/ethomson/poxygit/releases/download/v0.4.0/poxygit-0.4.0.jar >poxygit.jar
 
 	echo ""
 	echo "Starting HTTP server..."