I tried to build up the AOSP on Ubuntu 18.04.4 base on the official guide. All work look good until start emulator.
Step1:repo init -u https://android.googlesource.com/platform/manifest -b android-10.0.0_r29 --depth=1 --platform=auto
Step2:repo sync -qc -j4
Step3:source build/envsetup.sh
Step4:lunch aosp_arm64-eng
Step5:make -j4
Step6:emulator
root@simon-MS-7850:~/workspace/ANDROID_S# emulator
emulator: WARNING: Couldn't find crash service executable /root/workspace/ANDROID_S/prebuilts/android-emulator/linux-x86_64/emulator64-crash-service
emulator: WARNING: system partition size adjusted to match image file (3083 MB > 800 MB)
statvfs('/root/workspace/ANDROID_S/out/target/product/generic_arm64/snapshots/default_boot/ram.img') failed: No such file or directory
emulator: WARNING: encryption is off
pulseaudio: pa_context_connect() failed
pulseaudio: Reason: Connection refused
pulseaudio: Failed to initialize PA contextaudio: Could not init `pa' audio driver
The emulator started but stay at the blank screen and get the above error '...ot/ram.img') failed: No such file or directory'. I found a file ram.img.dirty in directory '.../default_boot/' instead of ram.img.
root@simon-MS-7850:~/workspace/ANDROID_S/out/target/product/generic_arm64/snapshots/default_boot# ls
ram.img.dirty snapshot.pb
No idea the key reason and how to fix it.