user6307: For minting a token, I compute the minimum amount as follows:
cardano-cli transaction calculate-min-required-utxo 
  --babbage-era                                     
  --protocol-params-file protocol-parameters.json   
  --tx-out "addr_test⋯pxzl 2000000 + 1 019b⋯55f5.766963"

This gives "Lovelace 1021470", which I'd plug into the --tx-out expression of the 'transaction build' command like this:
cardano-cli transaction build
  --testnet-magic 1
  --tx-in-collateral 3a0d⋯84af#3
  --tx-in 3a0d⋯84af#3
  --tx-in 616c⋯3486#1
  --tx-in f029⋯d21b#3
  --tx-out "addr_test⋯pxzl 1021470 + 1 019b⋯55f5.766963"
  --mint "1 019b⋯55f5.766963"
  --change-address addr_test⋯pxzl
  --protocol-params-file protocol-parameters.json
  --minting-script-file policy.script
  --out-file unsigned.json

But with cardano-cli 1.35.3, this gives me:
"Command failed: transaction build Error: Minimum UTxO threshold not met for tx output: 
addr_test⋯pxzl + 1021470 lovelace + 1 019b⋯55f5.766963"
Minimum required UTxO: Lovelace 1344720

The above procedure used to work perfectly with older cardano-cli 's (last one tested: cardano-cli-1.34.1)
Question: Is cardano-cli 1.35.3's calculate-min-required-utxo underestimating, or is there a new way to compute the min-required-utxo?

user1071: You're using calculate-min-required-utxo  with --babbage-era flag and build without any era flag. cardano-node 1.34.3 defaults to Alonzo-era.
There appears to be a bug for overestimation in this scenario: https://github.com/input-output-hk/cardano-node/issues/4297
Use --babbage-era for both cmds.

6307: <p>For minting a token, I compute the minimum amount as follows:</p>
<pre><code>cardano-cli transaction calculate-min-required-utxo 
  --babbage-era                                     
  --protocol-params-file protocol-parameters.json   
  --tx-out &quot;addr_test⋯pxzl 2000000 + 1 019b⋯55f5.766963&quot;
</code></pre>
<p>This gives &quot;Lovelace 1021470&quot;, which I'd plug into the <code>--tx-out</code> expression of the 'transaction build' command like this:</p>
<pre><code>cardano-cli transaction build
  --testnet-magic 1
  --tx-in-collateral 3a0d⋯84af#3
  --tx-in 3a0d⋯84af#3
  --tx-in 616c⋯3486#1
  --tx-in f029⋯d21b#3
  --tx-out &quot;addr_test⋯pxzl 1021470 + 1 019b⋯55f5.766963&quot;
  --mint &quot;1 019b⋯55f5.766963&quot;
  --change-address addr_test⋯pxzl
  --protocol-params-file protocol-parameters.json
  --minting-script-file policy.script
  --out-file unsigned.json
</code></pre>
<p>But with cardano-cli 1.35.3, this gives me:</p>
<pre><code>&quot;Command failed: transaction build Error: Minimum UTxO threshold not met for tx output: 
addr_test⋯pxzl + 1021470 lovelace + 1 019b⋯55f5.766963&quot;
Minimum required UTxO: Lovelace 1344720
</code></pre>
<p>The above procedure used to work perfectly with older cardano-cli 's (last one tested: cardano-cli-1.34.1)</p>
<p>Question: Is cardano-cli 1.35.3's calculate-min-required-utxo <strong>underestimating</strong>, or is there a <strong>new way</strong> to compute the min-required-utxo?</p>
 1071: <p>You're using <code>calculate-min-required-utxo </code> with <code>--babbage-era</code> flag and <code>build</code> without any era flag. cardano-node 1.34.3 defaults to Alonzo-era.</p>
<p>There appears to be a bug for overestimation in this scenario: <a href="https://github.com/input-output-hk/cardano-node/issues/4297" rel="nofollow noreferrer">https://github.com/input-output-hk/cardano-node/issues/4297</a></p>
<p>Use <code>--babbage-era</code> for both cmds.</p>
